Monoclonal antibodies against her2

ABSTRACT

Isolated monoclonal antibodies which bind to human epidermal growth factor receptor 2 (HER2), and related antibody-based compositions and molecules, are disclosed. Pharmaceutical compositions comprising the antibodies and therapeutic and diagnostic methods for using the antibodies are also disclosed.

RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.15/832,337, filed Dec. 5, 2017 (now U.S. Pat. No. 11,091,553), which isa divisional of U.S. patent application Ser. No. 13/700,341, filed Mar.14, 2013 (now U.S. Pat. No. 9,862,769), which is a 35 U.S.C. 371national stage filing of PCT/EP2011/058779, filed May 27, 2011, whichclaims priority to U.S. Provisional Application No. 61/349,180, filedMay 27, 2010, International Patent Application No. PCT/EP2011/056388,filed Apr. 20, 2011, and Danish Patent Application Nos. PA201100312,filed Apr. 20, 2011, and PA201000467, filed May 27, 2010. The contentsof the aforementioned applications are hereby incorporated by reference.

SEQUENCE LISTING

The instant application contains a Sequence Listing which has beensubmitted electronically in ASCII format and is hereby incorporated byreference in its entirety. Said ASCII copy, created on Jul. 7, 2021, isnamed GMI_131USDV4_Sequence_Listing.txt and is 149,745 bytes in size.

FIELD OF THE INVENTION

The present invention relates to monoclonal antibodies directed to humanepidermal growth factor receptor 2 (HER2) and to uses of suchantibodies, in particular their use in the treatment of cancer.

BACKGROUND OF THE INVENTION

HER2 is a 185-kDa cell surface receptor tyrosine kinase and member ofthe epidermal growth factor receptor (EGFR) family that comprises fourdistinct receptors: EGFR/ErbB-1, HER2/ErbB-2, HER3/ErbB-3, andHER4/ErbB-4. Both homo- and heterodimers are formed by the four membersof the EGFR family, with HER2 being the preferred and most potentdimerization partner for other ErbB receptors (Graus-Porta et al., EmboJ 1997; 16:1647-1655; Tao et al., J Cell Sci 2008; 121:3207-3217). HER2can be activated by overexpression or by heterodimerization with otherErbBs that can be activated by ligand binding (Riese and Stern,Bioessays 1998; 20:41-48). For HER2, no ligand has been identified. HER2activation leads to receptor phosphorylation, which triggers a cascadeof downstream signals through multiple signaling pathways, such as MAPK,phosphoinositol 3-kinase/AKT, JAK/STAT and PKC, which ultimately resultsin the regulation of multiple cellular functions, such as growth,survival and differentiation (Huang et al., Expert Opin Biol Ther 2009;9:97-110).

Much of the attention on HER2 in tumors has been focused on its role inbreast cancer, in which HER2 overexpression is reported in approximately20% of the cases and is correlated with poor prognosis (Reese et al.,Stem Cells 1997; 15:1-8; Andrechek et al., Proc Natl Acad Sci USA 2000;97:3444-3449; and Slamon et al., Science 1987; 235:177-182). Besidesbreast cancer, HER2 expression has also been associated with other humancarcinoma types, including prostate cancer, non-small cell lung cancer,bladder cancer, ovarian cancer, gastric cancer, colon cancer, esophagealcancer and squamous cell carcinoma of the head & neck (Garcia de Palazzoet al., Int J Biol Markers 1993; 8:233-239; Ross et al., Oncologist2003; 8:307-325; Osman et al., J Urol 2005; 174:2174-2177; Kapitanovicet al., Gastroenterology 1997; 112:1103-1113; Turken et al., Neoplasma2003; 50:257-261; and Oshima et al., Int J Biol Markers 2001;16:250-254).

Trastuzumab (Herceptin®) is a recombinant, humanized monoclonal antibodydirected against domain IV of the HER2 protein, thereby blockingligand-independent HER2 homodimerization, and to a lesser extendheterodimerization of HER2 with other family members in cells with highHER2 overexpression (Cho et al., Nature 2003; 421:756-760 and Wehrman etal., Proc Natl Acad Sci USA 2006; 103:19063-19068). In cells with modestHER2 expressing levels, trastuzumab was found to inhibit the formationof HER2/EGFR heterodimers (Wehrman et al., (2006), supra; Schmitz etal., Exp Cell Res 2009; 315:659-670). Trastuzumab mediatesantibody-dependent cellular cytotoxicity (ADCC) and prevents ectodomainshedding, which would otherwise result in the formation of a truncatedconstitutively active protein in HER2 overexpressing cells. Alsoinhibition of both in vitro and in vivo proliferation of tumor cellsexpressing high levels of HER2 has been reported for trastuzumab(reviewed in Nahta and Esteva, Oncogene 2007; 26:3637-3643). Herceptin®has been approved both for first-line and adjuvant treatment of HER2overexpressing metastatic breast cancer, either in combination withchemotherapy, or as a single agent following one or more chemotherapyregimens. Trastuzumab has been found to be effective only in 20-50% ofHER2 overexpressing breast tumor patients and many of the initialresponders show relapse after a few months (Dinh et al., Clin AdvHematol Oncol 2007; 5:707-717).

Pertuzumab (Omnitarg™) is another humanized monoclonal antibody. It isdirected against domain II of the HER2 protein, resulting in inhibitionof ligand-induced heterodimerization (i.e., HER2 dimerizing with anothermember of the ErbB family to which a ligand has bound); a mechanismreported to not strictly require high HER2 expression levels (Franklinet al., Cancer Cell 2004; 5:317-328.). Although pertuzumab also mediatesADCC, the main mechanism of action of pertuzumab relies on itsdimerization blockade (Hughes et al., Mol Cancer Ther 2009;8:1885-1892). Moreover, pertuzumab was found to enhance EGFRinternalization and downregulation by inhibiting the formation ofEGFR/HER2 heterodimers, which otherwise tethers EGFR at the plasmamembrane (Hughes et al., 2009, supra). This correlates with theobservation that EGFR homodimers internalize more efficient thanEGFR/HER2 dimers (Pedersen et al., Mol Cancer Res 2009; 7:275-284. Thecomplementary mechanisms of action of pertuzumab and trastuzumabreportedly results in enhanced anti-tumor effects and efficacy whencombined in patients who progressed during prior trastuzumab therapy(Baselga et al., J Clin Oncol 2010; 28:1138-1144), and a phase III trialto evaluate this antibody combination together with Docetaxel inpreviously untreated HER2-positive metastatic breast cancer is underway.

An alternative approach to improve targeted antibody therapy is bydelivering cytotoxic cells or drugs specifically to theantigen-expressing cancer cells. For example, the so-calledtrifunctional antibodies are bispecific antibodies, targeting with onearm the antigen on the tumor cell and with the other arm for instanceCD3 on T cells. Upon binding, a complex of T cells, tumor cells andeffector cells that bind Fc is formed, leading to killing of the tumorcells (Muller and Kontermann, BioDrugs 2010; 24:89-98.). Ertumaxomab isone such trifunctional antibody against HER2, which induces cytotoxicityin cell lines with low HER2 expression and which is in Phase II clinicaldevelopment in metastatic breast cancer (Jones et al., Lancet Oncol2009; 10:1179-1187 and Kiewe et al., Clin Cancer Res 2006;12:3085-3091).

A HER2 antibody drug conjugate (ADC) is currently in clinicaldevelopment. T-DM1 consists of trastuzumab conjugated to the fungaltoxin maytansine. In Phase II trials, responses in a heavily pretreatedpatient cohort including prior trastuzumab and/or lapatinib therapy werereported Burris et al, 2011, J Clin Oncol 29: 398-405 and Lewis Phillipset al., Cancer Res 2008; 68:9280-9290). Preliminary data from a Phase IItrial determining efficacy and safety of T-DM1 versus trastuzumab plusdocetaxel in her2-positive metastatic breast cancer patients with norior chemotherapy for metastatic disease were reported (Perez et al,Abstract BA3, European Society for Medical Oncology meeting 2010). APhase III trial to evaluate T-DM1 efficacy and safety versuscapecitabine+lapatinib in patients with HER2-positive locally advancedor metastatic breast cancer who received prior trastuzumab therapy isongoing.

While many factors are involved in selecting a suitable antibody forHER2 targeted therapy, it is typically an advantage for an ADC approachif the HER2-antibody complex efficiently internalizes upon antibodybinding. Studies on murine HER2 antibodies have shown that certaincombinations of antibodies instigate HER2 endocytosis (Ben-Kasus et al.,PNAS 2009; 106:3294-9). Human HER2 antibodies F5 and C1 have beenreported to internalize relatively rapidly on their own and to bind thesame epitope (WO 99/55367 and WO 2006/116107). As compared to EGFR,however, internalization of HER2 is impaired. Indeed, EGFR homodimersinternalize much more efficiently than HER2 homodimers (Dinh et al.,Clin Adv Hematol Oncol 2007; 5:707-717). EGFR, and also HER3, canincrease endocytosis of HER2 by the formation of EGFR/HER2 and HER3/HER2heterodimers, respectively (Baulida et al., J Biol Chem 1996;271:5251-5257; Pedersen N M, et al., Mol Cancer Res 2009; 7:275-84).

The complex mechanisms regulating the function of HER2 warrant furtherresearch on new and optimized therapeutic strategies against thisproto-oncogene. Accordingly, there remains a need for effective and safeproducts for treating HER2-related diseases, such as cancer.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide novel highlyspecific and effective monoclonal HER2 antibodies for medical use. Theantibodies of the invention exhibit HER2 binding characteristics thatdiffer from antibodies described in the art. Particularly, although mostof the antibodies apparently bind to HER2 segments overlapping withthose bound by trastuzumab, pertuzumab or F5/C1 as shown in across-blocking HER2 binding assay, the novel antibodies arecharacterized by a higher efficiency in killing HER2-expressing tumorcells in an ADC assay, improved internalization and/or other advantagesover the known antibodies.

In preferred embodiments, the antibodies of the invention are fullyhuman, bind to novel epitopes, and/or have favorable properties fortherapeutic use in human patients. Exemplary properties include, but arenot limited to, favorable binding characteristics to cancer cellsexpressing human HER2 at high or low levels, specific binding rhesusepithelial cells expressing a HER2 ortholog, efficient internalizationupon binding to HER2, high capacity for killing cancer cells expressinghigh- or low-levels of HER2 when administered as an ADC, promotingproliferation of HER2-expressing cells less than F5, a neutral orinhibitory effect on the proliferation of HER2-expressing cancer cells,and provide for effective ADCC-mediated killing of HER2-expressingcells, as well as any combination of the foregoing properties.

These and other aspects of the invention are described in further detailbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1K: Alignment of HuMab heavy chain variable region (VH)sequences with germline (reference) sequences (FIGS. 1A-1K). In each VHsequence, the amino acids that differ from those of the germline(reference) at specific positions are highlighted. Consensus VHsequences are shown, where “X” indicates positions at which alternativeamino acids (selected from those aligned at each position) are possible.The CDR1, CDR2, and CDR3 sequences are underlined in each VH sequence.The consensus CDR sequences are further defined in Table 4.

FIGS. 2A-2F: Alignment of HuMab light chain variable region (VL)sequences with germline (reference) sequences (FIGS. 2A-2B). In each VLsequence, the amino acids that differ from those of the germline(reference) at specific positions are highlighted. In FIG. 2A, all VLsequences derived from the same V-segment (IgKV1-12-01), but the closestJ-segment differed between antibodies. Consensus VL sequences are shown,where “X” indicates positions at which alternative amino acids (selectedfrom those aligned at the indicated position) are possible. The CDR1,CDR2, and CDR3 sequences are underlined in each VL sequence. Theconsensus CDR sequences are further defined in Table 4.

FIGS. 3A-3D: Binding curves of HER2 antibodies to (FIG. 3A, FIG. 3B)high (AU565) and (FIG. 3C, FIG. 3D) low (A431) HER2 expressing celllines, determined as described in Example 12. Data shown are meanfluorescence intensities (MFI) of one representative experiment for eachcell line. The EC₅₀ values indicate the apparent affinities.

FIG. 4: Binding of HER2 antibodies to HER2 expressed on monkey Rhesusepithelial cells. Data shown are mean fluorescence intensities (MFI) ofone experiment, described in Example 13.

FIG. 5: Chromium-release (ADCC) assay of HER2 antibodies, showingPBMC-mediated lysis of ⁵¹Cr-labeled SK-BR-3 cells after incubation withHER2 antibody. Values depicted are the mean maximum percentages⁵¹Cr-release t the standard deviation from one representative in vitroADCC experiment with SK-BR-3 cells. See Example 15 for details.

FIG. 6: Effect of HER2 antibodies on the proliferation of AU565 cells,as compared to untreated cells (set to 100%). Data shown are percentagesproliferation of AU565 cells compared to untreated cells measured inthree independent experiments t the standard deviation. * Significant(P<0.05). See Example 16 for details.

FIG. 7: Percentage of viable MCF7 cells stimulated with Heregulin-01 andtreated with the indicated HER2 antibodies, relative to cells stimulatedwith Heregulin-01 only. As a control, the percentage proliferation ofunstimulated cells is shown (none). Data was obtained from threeindependent experiments t the stdev. * Significant inhibition ofHeregulin-01-induced proliferation (P<0.05). See Example 17 for details.

FIGS. 8A-8D: ADC assay, showing killing of AU565 cells (FIG. 8A, FIG.8B) or A431 cells (FIG. 8C, FIG. 8D) via anti-kappa-ETA′-conjugated HER2antibodies. (FIG. 8A, FIG. 8B) Data shown are fluorescence intensities(FI) of one representative experiment with AU565 cells treated withnon-conjugated and anti-kappa-ETA′-conjugated HER2 antibodies. (FIG. 8C,FIG. 8D) Data shown are mean fluorescence intensities (MFI) of onerepresentative experiment with A431 cells treated with non-conjugatedand anti-kappa-ETA′-conjugated HER2 antibodies. See Example 18 fordetails.

FIG. 9: Killing of A431 cells induced by anti-kappa-ETA′ pre-incubatedHER2×HER2 bispecific antibodies. The viability of A431 cells after 3days incubation with HER2 antibodies, pre-incubated withanti-kappa-ETA′. Cell viability was quantified using Alamarblue. Datashown are fluorescence intensities (FI) of one experiment with A431cells treated with anti-kappa-ETA′-conjugated HER2 antibodies andHER2×HER2 bispecific antibodies. Staurosporin was used as positivecontrol, whereas an isotype control antibody was used as negativecontrol.

FIG. 10: HER2×HER2 bispecific molecules induced downmodulation of HER2receptor. Relative percentage of HER2 expression levels in AU565 celllysates after 3 days incubation with 10 μg/mL mAb. The amount of HER2was quantified using a HER2-specific capture ELISA and depicted aspercentage inhibition compared to untreated cells. Data shown is themean of two experiments plus standard deviation, except for combinationsof monospecific IgG1 antibodies which were tested once.

FIGS. 11A and 11B: Colocalization analysis of HER2×HER2 bispecificantibodies (FITC) with lysosomal marker LAMP1 (Cy5). FITC pixelintensity overlapping with Cy5 for various monospecific HER2 antibodiesand HER2×HER2 bispecific antibodies (FIG. 11A) FITC pixel intensity inLAMP1/Cy5 positive pixels of three different images is plotted for eachantibody tested. Monospecifics show lower FITC pixel intensities in theLAMP1/Cy5 positive pixels compared to bispecifics. FIG. 11B representsthe mean value of FITC pixel intensity per LAMP1/Cy5 positive pixelcalculated from the three different images. Together these resultsindicate that after internalization higher levels of bispecificantibodies, compared to monospecifics antibodies, localize to Lamp1/Cy5positive vesicles.

FIG. 12: Inhibition of proliferation by HER-2 mono and bispecificantibodies. AU565 cells were seeded in the presence of 10 μg/mL HER2antibody or HER2×HER2 bispecific antibody in serum-free cell culturemedium. After three days, the amount of viable cells was quantified withAlamarblue and cell viability was presented as a percentage relative tountreated cells. An isotype control antibody was used as negativecontrol. Data shown are percentage viable AU565 cells compared tountreated cells measured in five-fold t the standard deviation. *indicates only one data point was depicted.

FIG. 13: T cell mediated cytotoxicity of AU565 cells by HER2×CD3bispecific antibodies as well as by N297Q mutants of HER2×CD3 bispecificantibodies (bispecific indicated as Duo in the figure).

FIG. 14: Antibody induced downmodulation of HER2. Relative percentage ofHER2 expressed in AU565 cell lysate after 3 days incubation with 10μg/mL antibody. The amount of HER2 was quantified using a HER2-specificcapture ELISA and plotted as a percentage relative to untreated cells.Data shown are mean of three experiments±standard deviation.

FIG. 15: Colocalization analysis of HER2 antibodies (FITC) withlysosomal marker LAMP1 (Cy5). FITC pixel intensity overlapping with Cy5for various monospecific HER2 antibodies. FITC pixel intensity inLAMP1/Cy5 positive pixels of three different images is plotted for eachantibody. Group 3 antibodies 098 and 153 show higher FITC pixelintensities in the LAMP1/Cy5 positive compartments compared toantibodies 025 and pertuzumab from Group 2 and 169 and Herceptin fromGroup 1.

FIG. 16: HER2 antibody binding to CHO—S cells transfected with differentHER2 ECD construct analyzed by means of flow cytometry. Hu-HER2=fullyhuman HER2, Hu-HER2-ch(I) CR1=hu-HER2 with chicken domain I,Hu-HER2-ch(II)=hu-HER2 with chicken domain II, hu-HER2-ch(III)=hu-HER2with chicken domain III and Hu-HER2-ch(IV)=hu-HER2 with chicken domainIV. Data shown are mean fluorescence intensities (MFI) of onerepresentative antibody, TH1014-153. See example 25 for details.

FIGS. 17A and 17B: In vivo effect of HER2-HuMabs in the NCI-N87 humangastric carcinoma xenograft model in female CB.17 severe combinedimmunodeficiency (SCID) mice. Data shown are mean tumorsize S.E.M. pergroup (n=10 mice per group) (FIG. 17A) and survival (FIG. 17B). Seeexample 29 for details.

FIGS. 18A and 18B: In vivo effect of HER2 HuMabs in BT-474 breast tumorxenografts in Balb/C nude mice. Data shown are mean tumorsize t S.E.M.per group (n=8 mice per group) (FIG. 18A) and survival (FIG. 18B). Seeexample 30 for details.

DETAILED DESCRIPTION OF THE INVENTION Definitions

The term “HER2” (also known as ErbB-2, NEU, HER-2, and CD340), when usedherein, refers to human epidermal growth factor receptor 2 (SwissProtP04626) and includes any variants, isoforms and species homologs of HER2which are naturally expressed by cells, including tumor cells, or areexpressed on cells transfected with the HER2 gene. Species homologsinclude rhesus monkey HER2 (Macaca mulatta; Genbank accession No.GI:109114897).

The term “immunoglobulin” refers to a class of structurally relatedglycoproteins consisting of two pairs of polypeptide chains, one pair oflight (L) low molecular weight chains and one pair of heavy (H) chains,all four inter-connected by disulfide bonds. The structure ofimmunoglobulins has been well characterized. See for instanceFundamental Immunology Ch. 7 (Paul, W., ed., 2nd ed. Raven Press, N.Y.(1989)). Briefly, each heavy chain typically is comprised of a heavychain variable region (abbreviated herein as V_(H) or VH) and a heavychain constant region. The heavy chain constant region typically iscomprised of three domains, C_(H)1, C_(H)2, and C_(H)3. Each light chaintypically is comprised of a light chain variable region (abbreviatedherein as V_(L) or VL) and a light chain constant region. The lightchain constant region typically is comprised of one domain, C_(L). TheV_(H) and V_(L) regions may be further subdivided into regions ofhypervariability (or hypervariable regions which may be hypervariable insequence and/or form of structurally defined loops), also termedcomplementarity determining regions (CDRs), interspersed with regionsthat are more conserved, termed framework regions (FRs). Each V_(H) andV_(L) is typically composed of three CDRs and four FRs, arranged fromamino-terminus to carboxy-terminus in the following order: FR1, CDR1,FR2, CDR2, FR3, CDR3, FR4 (see also Chothia and Lesk J. Mol. Biol. 196,901-917 (1987)). Unless otherwise stated or contradicted by context, CDRsequences herein are identified according to IMGT rules (Brochet X.,Nucl Acids Res. 2008; 36:W503-508 and Lefranc M P., Nucleic AcidsResearch 1999; 27:209-212; see also internet http addressimgt.cines.fr/IMGT_vquest/vquest?livret=0&Option=humanIg. However, thenumbering of amino acid residues in an antibody sequence can also beperformed by the method described in Kabat et al., Sequences of Proteinsof Immunological Interest, 5th Ed. Public Health Service, NationalInstitutes of Health, Bethesda, Md. (1991) (phrases such as “variabledomain residue numbering as in Kabat”, “Kabat position” or “according toKabat” herein refer to this numbering system). Particularly, fornumbering of amino acids in the constant region, the EU index numberingsystem according to Kabat et al, supra, can be used. The Kabat numberingof residues may be determined for a given antibody by alignment atregions of homology of the sequence of the antibody with a “standard”Kabat numbered sequence.

The term “antibody” (Ab) in the context of the present invention refersto an immunoglobulin molecule, a fragment of an immunoglobulin molecule,or a derivative of either thereof, which has the ability to specificallybind to an antigen under typical physiological conditions with a halflife of significant periods of time, such as at least about 30 minutes,at least about 45 minutes, at least about one hour, at least about twohours, at least about four hours, at least about 8 hours, at least about12 hours, about 24 hours or more, about 48 hours or more, about 3, 4, 5,6, 7 or more days, etc., or any other relevant functionally-definedperiod (such as a time sufficient to induce, promote, enhance, and/ormodulate a physiological response associated with antibody binding tothe antigen and/or time sufficient for the antibody to recruit aneffector activity). The variable regions of the heavy and light chainsof the immunoglobulin molecule contain a binding domain that interactswith an antigen. The constant regions of the antibodies (Abs) maymediate the binding of the immunoglobulin to host tissues or factors,including various cells of the immune system (such as effector cells)and components of the complement system such as C1q, the first componentin the classical pathway of complement activation. A HER2 antibody mayalso be a bispecific antibody, diabody, or similar molecule (see forinstance PNAS USA 90(14), 6444-8 (1993) for a description of diabodies).Indeed, bispecific antibodies, diabodies, and the like, provided by thepresent invention may bind any suitable target in addition to a portionof HER2. As indicated above, the term antibody herein, unless otherwisestated or clearly contradicted by context, includes fragments of anantibody that are antigen-binding fragments, i.e., retain the ability tospecifically bind to the antigen. It has been shown that theantigen-binding function of an antibody may be performed by fragments ofa full-length antibody. Examples of antigen-binding fragmentsencompassed within the term “antibody” include (i) a Fab′ or Fabfragment, a monovalent fragment consisting of the V_(L), V_(H), C_(L)and C_(H)1 domains, or a monovalent antibody as described inWO2007059782 (Genmab); (ii) F(ab′)₂ fragments, bivalent fragmentscomprising two Fab fragments linked by a disulfide bridge at the hingeregion; (iii) a Fd fragment consisting essentially of the V_(H) andC_(H)1 domains; (iv) a Fv fragment consisting essentially of the V_(L)and V_(H) domains of a single arm of an antibody, (v) a dAb fragment(Ward et al., Nature 341, 544-546 (1989)), which consists essentially ofa V_(H) domain and also called domain antibodies (Holt et al; TrendsBiotechnol. 2003 November; 21(11):484-90); (vi) camelid or nanobodies(Revets et al; Expert Opin Biol Ther. 2005 January; 5(1):111-24) and(vii) an isolated complementarity determining region (CDR). Furthermore,although the two domains of the Fv fragment, V_(L) and V_(H), are codedfor by separate genes, they may be joined, using recombinant methods, bya synthetic linker that enables them to be made as a single proteinchain in which the V_(L) and V_(H) regions pair to form monovalentmolecules (known as single chain antibodies or single chain Fv (scFv),see for instance Bird et al., Science 242, 423-426 (1988) and Huston etal., PNAS USA 85, 5879-5883 (1988)). Such single chain antibodies areencompassed within the term antibody unless otherwise noted or clearlyindicated by context. Although such fragments are generally includedwithin the meaning of antibody, they collectively and each independentlyare unique features of the present invention, exhibiting differentbiological properties and utility. These and other useful antibodyfragments in the context of the present invention, as well as bispecificformats of such fragments, are discussed further herein. It also shouldbe understood that the term antibody, unless specified otherwise, alsoincludes polyclonal antibodies, monoclonal antibodies (mAbs),antibody-like polypeptides, such as chimeric antibodies and humanizedantibodies, and antibody fragments retaining the ability to specificallybind to the antigen (antigen-binding fragments) provided by any knowntechnique, such as enzymatic cleavage, peptide synthesis, andrecombinant techniques. An antibody as generated can possess anyisotype.

As used herein, “isotype” refers to the immunoglobulin class (forinstance IgG1, IgG2, IgG3, IgG4, IgD, IgA, IgE, or IgM) that is encodedby heavy chain constant region genes.

The term “monovalent antibody” means in the context of the presentinvention that an antibody molecule is capable of binding a singlemolecule of the antigen, and thus is not able of antigen crosslinking.

An “antibody deficient in effector function” or an“effector-function-deficient antibody” refers to an antibody which has asignificantly reduced or no ability to activate one or more effectormechanisms, such as complement activation or Fc receptor binding. Thus,effector-function deficient antibodies have significantly reduced or noability to mediate antibody-dependent cell-mediated cytotoxicity (ADCC)and/or complement-dependent cytotoxicity (CDC). An example of such anantibody is IgG4.

A “HER2 antibody” or “anti-HER2 antibody” is an antibody as describedabove, which binds specifically to the antigen HER2.

The term “human antibody”, as used herein, is intended to includeantibodies having variable and constant regions derived from humangermline immunoglobulin sequences. The human antibodies of the inventionmay include amino acid residues not encoded by human germlineimmunoglobulin sequences (e.g., mutations introduced by random orsite-specific mutagenesis in vitro or by somatic mutation in vivo).However, the term “human antibody”, as used herein, is not intended toinclude antibodies in which CDR sequences derived from the germline ofanother mammalian species, such as a mouse, have been grafted onto humanframework sequences.

As used herein, a human antibody is “derived from” a particular germlinesequence if the antibody is obtained from a system using humanimmunoglobulin sequences, for instance by immunizing a transgenic mousecarrying human immunoglobulin genes or by screening a humanimmunoglobulin gene library, and wherein the selected human antibody isat least 90%, such as at least 95%, for instance at least 96%, such asat least 97%, for instance at least 98%, or such as at least 99%identical in amino acid sequence to the amino acid sequence encoded bythe germline immunoglobulin gene. Typically, outside the heavy chainCDR3, a human antibody derived from a particular human germline sequencewill display no more than 20 amino acid differences, e.g. no more than10 amino acid differences, such as no more than 9, 8, 7, 6 or 5, forinstance no more than 4, 3, 2, or 1 amino acid difference from the aminoacid sequence encoded by the germline immunoglobulin gene.

In a preferred embodiment, the antibody of the invention is isolated. An“isolated antibody,” as used herein, is intended to refer to an antibodywhich is substantially free of other antibodies having differentantigenic specificities (for instance an isolated antibody thatspecifically binds to HER2 is substantially free of antibodies thatspecifically bind antigens other than HER2). An isolated antibody thatspecifically binds to an epitope, isoform or variant of HER2 may,however, have cross-reactivity to other related antigens, for instancefrom other species (such as HER2 species homologs). Moreover, anisolated antibody may be substantially free of other cellular materialand/or chemicals. In one embodiment of the present invention, two ormore “isolated” monoclonal antibodies having different antigen-bindingspecificities are combined in a well-defined composition.

When used herein in the context of two or more antibodies, the term“competes with” or “cross-competes with” indicates that the two or moreantibodies compete for binding to HER2, e.g. compete for HER2 binding inthe assay described in Example 14. An antibody “blocks” or“cross-blocks” one or more other antibodies from binding to HER2 if theantibody competes with the one or more other antibodies 25% or more,with 25%-74% representing “partial block” and 75%-100% representing“full block”, preferably as determined using the assay of Example 14.For some pairs of antibodies, competition or blocking in the assay ofthe Examples is only observed when one antibody is coated on the plateand the other is used to compete, and not vice versa. Unless otherwisedefined or negated by context, the terms “competes with”,“cross-competes with”, “blocks” or “cross-blocks” when used herein isalso intended to cover such pairs of antibodies.

The term “epitope” means a protein determinant capable of specificbinding to an antibody. Epitopes usually consist of surface groupings ofmolecules such as amino acids or sugar side chains and usually havespecific three dimensional structural characteristics, as well asspecific charge characteristics. Conformational and nonconformationalepitopes are distinguished in that the binding to the former but not thelatter is lost in the presence of denaturing solvents. The epitope maycomprise amino acid residues directly involved in the binding (alsocalled immunodominant component of the epitope) and other amino acidresidues, which are not directly involved in the binding, such as aminoacid residues which are effectively blocked or covered by thespecifically antigen binding peptide (in other words, the amino acidresidue is within the footprint of the specifically antigen bindingpeptide).

The term “monoclonal antibody” as used herein refers to a preparation ofantibody molecules of single molecular composition. A monoclonalantibody composition displays a single binding specificity and affinityfor a particular epitope. Accordingly, the term “human monoclonalantibody” refers to antibodies displaying a single binding specificitywhich have variable and constant regions derived from human germlineimmunoglobulin sequences. The human monoclonal antibodies may begenerated by a hybridoma which includes a B cell obtained from atransgenic or transchromosomal nonhuman animal, such as a transgenicmouse, having a genome comprising a human heavy chain transgene and alight chain transgene, fused to an immortalized cell.

As used herein, the term “binding” in the context of the binding of anantibody to a predetermined antigen or epitope typically is a bindingwith an affinity corresponding to a K_(D) of about 10⁻⁷ M or less, suchas about 10⁻⁸ M or less, such as about 10⁻⁹ M or less, about 10⁻¹⁰ M orless, or about 10⁻¹¹ M or even less when determined by for instancesurface plasmon resonance (SPR) technology in a BIAcore 3000 instrumentusing the antigen as the ligand and the antibody as the analyte, andbinds to the predetermined antigen with an affinity corresponding to aK_(D) that is at least ten-fold lower, such as at least 100 fold lower,for instance at least 1,000 fold lower, such as at least 10,000 foldlower, for instance at least 100,000 fold lower than its affinity forbinding to a non-specific antigen (e.g., BSA, casein) other than thepredetermined antigen or a closely-related antigen. The amount withwhich the affinity is lower is dependent on the K_(D) of the antibody,so that when the K_(D) of the antibody is very low (that is, theantibody is highly specific), then the amount with which the affinityfor the antigen is lower than the affinity for a non-specific antigenmay be at least 10,000 fold.

The term “k_(d)” (sec⁻¹), as used herein, refers to the dissociationrate constant of a particular antibody-antigen interaction. Said valueis also referred to as the k_(off) value.

The term “k_(a)” (M⁻¹×sec⁻¹), as used herein, refers to the associationrate constant of a particular antibody-antigen interaction.

The term “K_(D)” (M), as used herein, refers to the dissociationequilibrium constant of a particular antibody-antigen interaction.

The term “K_(A)” (M⁻¹), as used herein, refers to the associationequilibrium constant of a particular antibody-antigen interaction and isobtained by dividing the k_(a) by the k_(d).

As used herein, the term “inhibits proliferation” (e.g. referring tocells, such as tumor cells) is intended to include any substantialdecrease in the cell proliferation when contacted with a HER2 antibodyas compared to the proliferation of the same cells not in contact with aHER2 antibody, e.g., the inhibition of proliferation of a cell cultureby at least about 10%, at least about 20% or at least about 30%, or atleast as much as a reference antibody such as trastuzumab, e.g., asdetermined by an assay in the Examples, e.g. example 16.

As used herein, the term “promotes proliferation” (e.g. referring tocells, such as tumor cells) is intended to include any substantialincrease in the cell proliferation when contacted with a HER2 antibodyas compared to the proliferation of the same cells not in contact with aHER2 antibody, e.g., the promotion of proliferation of a cell culture byat least about 10%, at least about 20% or at least about 30%, or atleast as much as a reference antibody as F5, e.g., as determined by anassay in the Examples.

As used herein, the term “internalization”, when used in the context ofa HER2 antibody includes any mechanism by which the antibody isinternalized into a HER2-expressing cell from the cell-surface and/orfrom surrounding medium, e.g., via endocytosis. The internalization ofan antibody can be evaluated using a direct assay measuring the amountof internalized antibody (such as, e.g., the fab-CypHer5E assaydescribed in Example 18), or an indirect assay where the effect of aninternalized antibody-toxin conjugate is measured (such as, e.g., theanti-kappa-ETA′ assay of Example 17).

The present invention also provides antibodies comprising functionalvariants of the V_(L) region, V_(H) region, or one or more CDRs of theantibodies of the examples. A functional variant of a V_(L), V_(H), orCDR used in the context of a HER2 antibody still allows the antibody toretain at least a substantial proportion (at least about 50%, 60%, 70%,80%, 90%, 95% or more) of the affinity/avidity and/or thespecificity/selectivity of the parent antibody and in some cases such aHER2 antibody may be associated with greater affinity, selectivityand/or specificity than the parent antibody.

Such functional variants typically retain significant sequence identityto the parent antibody. The percent identity between two sequences is afunction of the number of identical positions shared by the sequences(i.e., % homology=# of identical positions/total # of positions×100),taking into account the number of gaps, and the length of each gap,which need to be introduced for optimal alignment of the two sequences.The percent identity between two nucleotide or amino acid sequences maye.g. be determined using the algorithm of E. Meyers and W. Miller,Comput. Appl. Biosci 4, 11-17 (1988) which has been incorporated intothe ALIGN program (version 2.0), using a PAM120 weight residue table, agap length penalty of 12 and a gap penalty of 4. In addition, thepercent identity between two amino acid sequences may be determinedusing the Needleman and Wunsch, J. Mol. Biol. 48, 444-453 (1970)algorithm.

Exemplary variants include those which differ from a parent antibody VHand/or VL sequence shown in FIGS. 1 and 2 at one or more “variant” aminoacid positions, denoted “X” in the corresponding consensus sequence.Preferred variants are those in which the new amino acid is selectedfrom those at the corresponding position in one of the aligned sequencesin FIG. 1 or 2 (for details on CDR sequence variants, see Table 4).Alternatively or additionally, the sequence of VH, VL or CDR variantsmay differ from the sequence of the VH, VL or CDR of the parent antibodysequences mainly by conservative substitutions; for instance at least10, such as at least 9, 8, 7, 6, 5, 4, 3, 2 or 1 of the substitutions inthe variant are conservative amino acid residue replacements.

In the context of the present invention, conservative substitutions maybe defined by substitutions within the classes of amino acids reflectedin the following table:

Amino acid residue classes for conservative substitutions AcidicResidues Asp (D) and Glu (E) Basic Residues Lys (K), Arg (R), and His(H) Hydrophilic Uncharged Ser (S), Thr (T), Asn (N), and Residues Gln(Q) Aliphatic Uncharged Gly (G), Ala (A), Val (V), Leu (L), Residues andIle (I) Non-polar Uncharged Cys (C), Met (M), and Pro (P) ResiduesAromatic Residues Phe (F), Tyr (Y), and Trp (W)

The term “recombinant host cell” (or simply “host cell”), as usedherein, is intended to refer to a cell into which an expression vectorhas been introduced, e.g. an expression vector encoding an antibody ofthe invention. Recombinant host cells include, for example,transfectomas, such as CHO cells, HEK293 cells, NS/0 cells, andlymphocytic cells.

The term “transgenic non-human animal” refers to a non-human animalhaving a genome comprising one or more human heavy and/or light chaintransgenes or transchromosomes (either integrated or non-integrated intothe animal's natural genomic DNA) and which is capable of expressingfully human antibodies. For example, a transgenic mouse can have a humanlight chain transgene and either a human heavy chain transgene or humanheavy chain transchromosome, such that the mouse produces human HER2antibodies when immunized with HER2 antigen and/or cells expressingHER2. The human heavy chain transgene may be integrated into thechromosomal DNA of the mouse, as is the case for transgenic mice, forinstance HuMAb mice, such as HCo7, HCo12, or HCo17 mice, or the humanheavy chain transgene may be maintained extrachromosomally, as is thecase for transchromosomal KM mice as described in WO02/43478. Similarmice, having a larger human Ab gene repertoire, include HCo7 and HCo20(see e.g. WO2009097006). Such transgenic and transchromosomal mice(collectively referred to herein as “transgenic mice”) are capable ofproducing multiple isotypes of human monoclonal antibodies to a givenantigen (such as IgG, IgA, IgM, IgD and/or IgE) by undergoing V-D-Jrecombination and isotype switching. Transgenic, nonhuman animal canalso be used for production of antibodies against a specific antigen byintroducing genes encoding such specific antibody, for example byoperatively linking the genes to a gene which is expressed in the milkof the animal.

“Treatment” refers to the administration of an effective amount of atherapeutically active compound of the present invention with thepurpose of easing, ameliorating, arresting or eradicating (curing)symptoms or disease states.

An “effective amount” or “therapeutically effective amount” refers to anamount effective, at dosages and for periods of time necessary, toachieve a desired therapeutic result. A therapeutically effective amountof a HER2 antibody may vary according to factors such as the diseasestate, age, sex, and weight of the individual, and the ability of theHER2 antibody to elicit a desired response in the individual. Atherapeutically effective amount is also one in which any toxic ordetrimental effects of the antibody or antibody portion are outweighedby the therapeutically beneficial effects.

An “anti-idiotypic” antibody is an antibody which recognizes uniquedeterminants generally associated with the antigen-binding site of anantibody.

Further Aspects and Embodiments of the Invention

As described above, in a first aspect, the invention relates to amonoclonal antibody which binds HER2.

Monoclonal antibodies of the present invention may be produced, e.g., bythe hybridoma method first described by Kohler et al., Nature 256, 495(1975), or may be produced by recombinant DNA methods. Monoclonalantibodies may also be isolated from phage antibody libraries using thetechniques described in, for example, Clackson et al., Nature 352,624-628 (1991) and Marks et al., J. Mol. Biol. 222, 581-597 (1991).Monoclonal antibodies may be obtained from any suitable source. Thus,for example, monoclonal antibodies may be obtained from hybridomasprepared from murine splenic B cells obtained from mice immunized withan antigen of interest, for instance in form of cells expressing theantigen on the surface, or a nucleic acid encoding an antigen ofinterest. Monoclonal antibodies may also be obtained from hybridomasderived from antibody-expressing cells of immunized humans or non-humanmammals such as rats, dogs, primates, etc.

In one embodiment, the antibody of the invention is a human antibody.Human monoclonal antibodies directed against HER2 may be generated usingtransgenic or transchromosomal mice carrying parts of the human immunesystem rather than the mouse system. Such transgenic andtranschromosomic mice include mice referred to herein as HuMAb mice andKM mice, respectively, and are collectively referred to herein as“transgenic mice”.

The HuMAb mouse contains a human immunoglobulin gene miniloci thatencodes unrearranged human heavy (μ and γ) and κ light chainimmunoglobulin sequences, together with targeted mutations thatinactivate the endogenous μ and κ chain loci (Lonberg, N. et al., Nature368, 856-859 (1994)). Accordingly, the mice exhibit reduced expressionof mouse IgM or κ and in response to immunization, the introduced humanheavy and light chain transgenes, undergo class switching and somaticmutation to generate high affinity human IgG,κ monoclonal antibodies(Lonberg, N. et al. (1994), supra; reviewed in Lonberg, N. Handbook ofExperimental Pharmacology 113, 49-101 (1994), Lonberg, N. and Huszar,D., Intern. Rev. Immunol. Vol. 13 65-93 (1995) and Harding, F. andLonberg, N. Ann. N.Y. Acad. Sci 764 536-546 (1995)). The preparation ofHuMAb mice is described in detail in Taylor, L. et al., Nucleic AcidsResearch 20, 6287-6295 (1992), Chen, J. et al., International Immunology5, 647-656 (1993), Tuaillon et al., J. Immunol. 152, 2912-2920 (1994),Taylor, L. et al., International Immunology 6, 579-591 (1994), Fishwild,D. et al., Nature Biotechnology 14, 845-851 (1996). See also U.S. Pat.Nos. 5,545,806, 5,569,825, 5,625,126, 5,633,425, 5,789,650, 5,877,397,5,661,016, 5,814,318, 5,874,299, 5,770,429, 5,545,807, WO 98/24884, WO94/25585, WO 93/1227, WO 92/22645, WO 92/03918 and WO 01/09187.

The HCo7, HCo12, HCo17 and HCo20 mice have a JKD disruption in theirendogenous light chain (kappa) genes (as described in Chen et al., EMBOJ. 12, 821-830 (1993)), a CMD disruption in their endogenous heavy chaingenes (as described in Example 1 of WO 01/14424), and a KCo5 human kappalight chain transgene (as described in Fishwild et al., NatureBiotechnology 14, 845-851 (1996)). Additionally, the Hco7 mice have aHCo7 human heavy chain transgene (as described in U.S. Pat. No.5,770,429), the HCo12 mice have a HCo12 human heavy chain transgene (asdescribed in Example 2 of WO 01/14424), the HCo17 mice have a HCo17human heavy chain transgene (as described in Example 2 of WO 01/09187)and the HCo20 mice have a HCo20 human heavy chain transgene. Theresulting mice express human immunoglobulin heavy and kappa light chaintransgenes in a background homozygous for disruption of the endogenousmouse heavy and kappa light chain loci.

In the KM mouse strain, the endogenous mouse kappa light chain gene hasbeen homozygously disrupted as described in Chen et al., EMBO J. 12,811-820 (1993) and the endogenous mouse heavy chain gene has beenhomozygously disrupted as described in Example 1 of WO 01/09187. Thismouse strain carries a human kappa light chain transgene, KCo5, asdescribed in Fishwild et al., Nature Biotechnology 14, 845-851 (1996).This mouse strain also carries a human heavy chain transchromosomecomposed of chromosome 14 fragment hCF (SC20) as described in WO02/43478. HCo12-Balb/C mice can be generated by crossing HCo12 toKCo5[J/K](Balb) as described in WO/2009/097006.

Splenocytes from these transgenic mice may be used to generatehybridomas that secrete human monoclonal antibodies according to wellknown techniques.

Further, human antibodies of the present invention or antibodies of thepresent invention from other species may be identified throughdisplay-type technologies, including, without limitation, phage display,retroviral display, ribosomal display, and other techniques, usingtechniques well known in the art and the resulting molecules may besubjected to additional maturation, such as affinity maturation, as suchtechniques are well known in the art (see for instance Hoogenboom etal., J. Mol. Biol. 227, 381 (1991) (phage display), Vaughan et al.,Nature Biotech 14, 309 (1996) (phage display), Hanes and Plucthau, PNASUSA 94, 4937-4942 (1997) (ribosomal display), Parmley and Smith, Gene73, 305-318 (1988) (phage display), Scott TIBS 17, 241-245 (1992),Cwirla et al., PNAS USA 87, 6378-6382 (1990), Russel et al., Nucl. AcidsResearch 21, 1081-1085 (1993), Hogenboom et al., Immunol. Reviews 130,43-68 (1992), Chiswell and McCafferty TIBTECH 10, 80-84 (1992), and U.S.Pat. No. 5,733,743). If display technologies are utilized to produceantibodies that are not human, such antibodies may be humanized.

Antibodies of Cross-Block Group 1

In one aspect of the antibody of the invention, the antibody binds thesame epitope on HER2 as one or more of the novel human antibodies ofcross-block group 1 described herein.

In one embodiment, the antibody cross-blocks the binding to soluble HER2of trastuzumab, when determined as described in Example 14.

In one embodiment, the antibody binds the same epitope as a referenceantibody comprising a VH region comprising the sequence of SEQ ID NO:1and a VL region comprising the sequence of SEQ ID NO:5 (169).

In one embodiment, the antibody binds the same epitope as a referenceantibody comprising a VH region comprising the sequence of SEQ ID NO:8and a VL region comprising the sequence of SEQ ID NO: 12 (050).

In one embodiment, the antibody binds the same epitope as a referenceantibody comprising a VH region comprising the sequence of SEQ ID NO:15and a VL region comprising the sequence of SEQ ID NO:84 (084).

In one embodiment, the antibody binds to the same epitope as a referenceantibody comprising VH and VL regions selected from the group consistingof:

-   -   a) a VH region comprising the sequence of SEQ ID NO:77 and a VL        region comprising the sequence of SEQ ID NO:78 (049);    -   b) a VH region comprising the sequence of SEQ ID NO:79 and a VL        region comprising the sequence of SEQ ID NO:80 (051);    -   c) a VH region comprising the sequence of SEQ ID NO:81 and a VL        region comprising the sequence of SEQ ID NO:82 (055);    -   d) a VH region comprising the sequence of SEQ ID NO:83 and a VL        region comprising the sequence of SEQ ID NO:84 (123);    -   e) a VH region comprising the sequence of SEQ ID NO:85 and a VL        region comprising the sequence of SEQ ID NO:86 (161); and    -   f) a VH region comprising the sequence of SEQ ID NO:87 and a VL        region comprising the sequence of SEQ ID NO:88 (124).

In another additional or alternative aspect of the antibody of theinvention, the antibody binds to HER2 and comprises a VH CDR3, VH regionand/or VL region sequence similar or identical to a sequence of thenovel antibodies described herein.

In one embodiment, the antibody comprises a VH CDR3 region having asequence selected from the group consisting of

SEQ ID NO:11 (050, 049, 051, 055), optionally wherein the VH region isderived from the IgHV3-21-1 germline sequence;

SEQ ID No: 130, such as the sequence of SEQ ID NO: 18 (084), optionallywherein the VH region is derived from the IgHV1-69-04 germline sequence;

SEQ ID NO: 133 (169, 123, 161, 124), such as the sequence of SEQ ID NO:4(169), optionally wherein the VH region is derived from the IgHV1-18-1germline sequence; or

In one embodiment, the antibody comprises a VH CDR3 region of one ofantibodies 123, 161, or 124, as shown in FIG. 1, optionally wherein theVH region is derived from an IgHV1-18-1 germline.

In one embodiment, the antibody comprises a VH region selected from thegroup consisting of

-   -   a) a VH region comprising the CDR1, CDR2 and CDR3 sequences of        SEQ ID NOs:9, 127 and 11, such as the CDR1, CDR2 and CDR3        sequences of SEQ ID NOS: 9, 10 and 11 (050); optionally where        the VH region is derived from an IgHV3-23-1 germline;    -   b) a VH region comprising the CDR1, CDR2 and CDR3 sequences of        SEQ ID NOs:128, 129 and 130, such the CDR1, CDR2 and CDR3        sequences of SEQ ID NOs:16, 17 and 18, respectively (084),        optionally where the VH region is derived from an IgHV1-69-04        germline; and    -   c) a VH region comprising the CDR1, CDR2, and CDR3 sequences of        SEQ ID NOs:131, 132, and 133, such as the CRD1, CDR2, and CDR3        sequences of SEQ ID NOs: 2, 3 and 4 (169), respectively,        optionally where the VH region is derived from an IgHV1-18-1        germline.

In one embodiment, the antibody comprises a VH region selected from thepreceding embodiments (a) or (b) and a VL region comprising the CDR1,CDR2, and CDR3 sequences of SEQ ID NO: 13, XAS (wherein X is A or V),and SEQ ID No: 155, respectively, such as a CDR1 sequence selected fromSEQ ID Nos: 13 or 20, a CDR2 which is AAS or VAS, and a CDR3 sequenceselected from SEQ ID NOs:14 and 21 (050, 084); respectively, optionallywhere the VL region is derived from an IgKV1-12-01 germline.

In one embodiment, the antibody comprises a VH region which is thepreceding embodiment (c) and a VL region comprising the CDR1, CDR2, andCDR3 sequences of SEQ ID NO:6, DXS (wherein X=A or T), and SEQ ID NO:156(169), respectively, optionally wherein the VL region is derived fromIgKV3-11-01.

In one embodiment, the antibody comprises a VH region comprising theCDR1, CDR2 and CDR3 sequences of SEQ ID NOs:2, 3 and 4, respectively;and a VL region comprising the CDR1, CDR2 and CDR3 sequences of SEQ IDNOs:6, DAS, and SEQ ID NO:7, respectively (169).

In one embodiment, the antibody comprises a VH region comprising theCDR1, CDR2 and CDR3 sequences of SEQ ID NOs:9, 10 and 11, respectively;and a VL region comprising the CDR1, CDR2 and CDR3 sequences of SEQ IDNOs:13, AAS, and SEQ ID NO: 14, respectively (050).

In one embodiment, the antibody comprises a VH region comprising theCDR1, CDR2 and CDR3 sequences of SEQ ID NOs:16, 17 and 18, respectively;and a VL region comprising the CDR1, CDR2 and CDR3 sequences of SEQ IDNOs:20, VAS, and SEQ ID NO:21, respectively (084).

In separate embodiments, the antibody comprises:

-   -   a) a VH region comprising the sequence of SEQ ID NO:1 and,        preferably, a VL region comprising the sequence of SEQ ID NO:5        (169);    -   b) a VH region comprising the sequence of SEQ ID NO:8 and,        preferably, a VL region comprising the sequence of SEQ ID NO: 12        (050);    -   c) a VH region comprising the sequence of SEQ ID NO: 15 and,        preferably, a VL region comprising the sequence of SEQ ID NO: 19        (084);    -   d) a VH region comprising the sequence of SEQ ID NO:77 and,        preferably, a VL region comprising the sequence of SEQ ID NO:78        (049);    -   e) a VH region comprising the sequence of SEQ ID NO:79 and,        preferably, a VL region comprising the sequence of SEQ ID NO:80        (051);    -   f) a VH region comprising the sequence of SEQ ID NO:81 and,        preferably, a VL region comprising the sequence of SEQ ID NO:82        (055);    -   g) a VH region comprising the sequence of SEQ ID NO:83 and,        preferably, a VL region comprising the sequence of SEQ ID NO:84        (123);    -   h) a VH region comprising the sequence of SEQ ID NO:85 and,        preferably, a VL region comprising the sequence of SEQ ID NO:86        (161);    -   i) a VH region comprising the sequence of SEQ ID NO:87 and,        preferably, a VL region comprising the sequence of SEQ ID NO:88        (124); and/or    -   j) a variant of any of said antibodies, wherein said variant        preferably has at most 1, 2 or 3 amino-acid modifications, more        preferably amino-acid substitutions, such as conservative amino        acid substitutions and substitutions where the new amino acid is        one at the same position in an aligned sequence in FIG. 1 or 2,        particularly at positions indicated by “X” in the corresponding        consensus sequence.

Antibodies of Cross-Block Group 2

In one aspect of the antibody of the invention, the antibody binds thesame epitope on HER2 as one or more of the novel human antibodies ofcross-block group 2 described herein.

In one embodiment, the antibody cross-blocks the binding to soluble HER2of pertuzumab, when determined as described in Example 14.

In one embodiment, the antibody binds the same epitope as a referenceantibody comprising a VH region comprising the sequence of SEQ ID NO:22and a VL region comprising the sequence of SEQ ID NO:26 (025).

In one embodiment, the antibody binds the same epitope as a referenceantibody comprising a VH region comprising the sequence of SEQ ID NO:29and a VL region comprising the sequence of SEQ ID NO:32 (091).

In one embodiment, the antibody binds the same epitope as a referenceantibody comprising a VH region comprising the sequence of SEQ ID NO:35and a VL region comprising the sequence of SEQ ID NO:39 (129).

In one embodiment, the antibody binds to the same epitope as a referenceantibody comprising VH and VL regions selected from the group consistingof:

-   -   a) a VH region comprising the sequence of SEQ ID NO:89 and a VL        region comprising the sequence of SEQ ID NO:90 (001);    -   b) a VH region comprising the sequence of SEQ ID NO:91 and a VL        region comprising the sequence of SEQ ID NO:92 (143);    -   c) a VH region comprising the sequence of SEQ ID NO:93 and a VL        region comprising the sequence of SEQ ID NO:94 (019);    -   d) a VH region comprising the sequence of SEQ ID NO:95 and a VL        region comprising the sequence of SEQ ID NO:96 (021);    -   e) a VH region comprising the sequence of SEQ ID NO:97 and a VL        region comprising the sequence of SEQ ID NO:98 (027);    -   f) a VH region comprising the sequence of SEQ ID NO:99 and a VL        region comprising the sequence of SEQ ID NO: 100 (032)    -   g) a VH region comprising the sequence of SEQ ID NO: 101 and a        VL region comprising the sequence of SEQ ID NO: 102 (035);    -   h) a VH region comprising the sequence of SEQ ID NO: 103 and a        VL region comprising the sequence of SEQ ID NO: 104 (036);    -   i) a VH region comprising the sequence of SEQ ID NO: 105 and a        VL region comprising the sequence of SEQ ID NO: 106 (054); and    -   j) a VH region comprising the sequence of SEQ ID NO: 107 and a        VL region comprising the sequence of SEQ ID NO: 108 (094).

In another additional or alternative aspect of the antibody of theinvention, the antibody binds to HER2 and comprises a VH CDR3, VH regionand/or VL region sequence similar or identical to a sequence of thenovel antibodies described herein.

In one embodiment, the antibody comprises a VH CDR3 region having asequence selected from the group consisting of

SEQ ID NO: 136, such as the sequence of SEQ ID NO:25 (025), optionallywherein the VH region is derived from the IgHV4-34-1 germline sequence;

SEQ ID NO: 139, such as the sequence of SEQ ID NO:31 (091), optionallywherein the VH region is derived from the IgHV4-34-01 germline sequence;and

SEQ ID NO: 142, such as the sequence of SEQ ID NO:38 (129), optionallywherein the VH region is derived from the IgHV3-30-01 germline sequence.

In one embodiment, the antibody comprises a VH CDR3 region of one ofantibodies 001, 143, 019, 021, 027, 032, 035, 036, 054 or 094 as shownin FIG. 1, optionally wherein the VH region is derived from anIgHV4-34-1 germline.

In one embodiment, the antibody comprises a VH region selected from thegroup consisting of

-   -   a) a VH region comprising the CDR1, CDR2 and CDR3 sequences of        SEQ ID NOs:134, 135 and 136, such as the CDR1, CDR2 and CDR3        sequences of SEQ ID NOS: 23, 24 and 25 (025); optionally where        the VH region is derived from an IgHV4-34-1 germline;    -   b) a VH region comprising the CDR1, CDR2 and CDR3 sequences of        SEQ ID NOs:137, 138 and 139, such the CDR1, CDR2 and CDR3        sequences of SEQ ID NOs:30, 163, and 31, respectively (091),        optionally where the VH region is derived from an IgHV4-34-01        germline; and    -   c) a VH region comprising the CDR1, CDR2, and CDR3 sequences of        SEQ ID NOs:140, 141 and 142, such as the CRD1, CDR2, and CDR3        sequences of SEQ ID NOs: 36, 37 and 38 (129), respectively,        optionally where the VH region is derived from an IgHV3-30-01        germline.

In one embodiment, the antibody comprises a VH region selected from thepreceding embodiment (a) and a VL region comprising the CDR1, CDR2, andCDR3 sequences of SEQ ID NO: 157, AAS, and SEQ ID No: 164, respectively,such as the CDR1, CDR2, and CDR3 sequences of SEQ ID Nos:27, AAS, andSEQ ID NO:28 (025); respectively, optionally where the VL region isderived from an IgKV1D-16-01 germline.

In one embodiment, the antibody comprises a VH region selected from thepreceding embodiment (b) and a VL region comprising the CDR1, CDR2, andCDR3 sequences of SEQ ID NO:33, AX₁X₂ (wherein X₁ is A or T, preferablyA; and X₂ is S or F, preferably S), and SEQ ID No: 158, respectively,such as the CDR1, CDR2 and CDR3 sequences of SEQ ID Nos:33, AAS, and SEQID NO:34 (091); respectively, optionally where the VL region is derivedfrom an IgKV1D-16-01 germline.

In one embodiment, the antibody comprises a VH region which is thepreceding embodiment (c) and a VL region comprising the CDR1, CDR2, andCDR3 sequences of SEQ ID NO:40, DAS and SEQ ID NO:41 (129),respectively, optionally wherein the VL region is derived fromIgKV3-11-01.

In one embodiment, the antibody comprises a VH region comprising theCDR1, CDR2 and CDR3 sequences of SEQ ID NOs:23, 24 and 25, respectively;and a VL region comprising the CDR1, CDR2 and CDR3 sequences of SEQ IDNOs:27, AAS, and SEQ ID NO:28, respectively (025).

In one embodiment, the antibody comprises a VH region comprising theCDR1, CDR2 and CDR3 sequences of SEQ ID NOs:30, 163 and 31,respectively; and a VL region comprising the CDR1, CDR2 and CDR3sequences of SEQ ID NOs:33, AAS, and SEQ ID NO:34, respectively (091).

In one embodiment, the antibody comprises a VH region comprising theCDR1, CDR2 and CDR3 sequences of SEQ ID NOs:36, 37 and 38, respectively;and a VL region comprising the CDR1, CDR2 and CDR3 sequences of SEQ IDNOs:40, DAS, and SEQ ID NO:41, respectively (129).

In separate embodiments, the antibody comprises:

-   -   a) a VH region comprising the sequence of SEQ ID NO:22 and,        preferably, a VL region comprising the sequence of SEQ ID NO:26        (025);    -   b) a VH region comprising the sequence of SEQ ID NO:29 and,        preferably, a VL region comprising the sequence of SEQ ID NO:32        (091);    -   c) a VH region comprising the sequence of SEQ ID NO:35 and,        preferably, a VL region comprising the sequence of SEQ ID NO:39        (129);    -   d) a VH region comprising the sequence of SEQ ID NO:89 and,        preferably, a VL region comprising the sequence of SEQ ID NO:90        (001);    -   e) a VH region comprising the sequence of SEQ ID NO:91 and,        preferably, a VL region comprising the sequence of SEQ ID NO:92        (143);    -   f) a VH region comprising the sequence of SEQ ID NO:93 and,        preferably, a VL region comprising the sequence of SEQ ID NO:94        (019);    -   g) a VH region comprising the sequence of SEQ ID NO:95 and,        preferably, a VL region comprising the sequence of SEQ ID NO:96        (021);    -   h) a VH region comprising the sequence of SEQ ID NO:97 and,        preferably, a VL region comprising the sequence of SEQ ID NO:98        (027);    -   i) a VH region comprising the sequence of SEQ ID NO:99 and,        preferably, a VL region comprising the sequence of SEQ ID NO:        100 (032);    -   j) a VH region comprising the sequence of SEQ ID NO: 101 and,        preferably, a VL region comprising the sequence of SEQ ID NO:        102 (035);    -   k) a VH region comprising the sequence of SEQ ID NO: 103 and,        preferably, a VL region comprising the sequence of SEQ ID NO:        104 (036);    -   l) a VH region comprising the sequence of SEQ ID NO: 105 and,        preferably, a VL region comprising the sequence of SEQ ID NO:        106 (054);    -   m) a VH region comprising the sequence of SEQ ID NO: 106 and,        preferably, a VL region comprising the sequence of SEQ ID NO:        108 (094); and/or    -   n) a variant of any of said antibodies, wherein said variant        preferably has at most 1, 2 or 3 amino-acid modifications, more        preferably amino-acid substitutions, such as conservative amino        acid substitutions and substitutions where the new amino acid is        one at the same position in an aligned sequence in FIG. 1 or 2,        particularly at positions indicated by “X” in the corresponding        consensus sequence.

Antibodies of Cross-Block Group 3

In one aspect of the antibody of the invention, the antibody binds thesame epitope on HER2 as one or more of the novel human antibodies ofcross-block group 3 described herein.

In one embodiment, the antibody cross-blocks the binding to soluble HER2of F5 and/or C5, when determined as described in Example 14.

In one embodiment, the antibody binds the same epitope as a referenceantibody comprising a VH region comprising the sequence of SEQ ID NO:46and a VL region comprising the sequence of SEQ ID NO:49 (127).

In one embodiment, the antibody binds the same epitope as a referenceantibody comprising a VH region comprising the sequence of SEQ ID NO:49and a VL region comprising the sequence of SEQ ID NO:53 (159).

In one embodiment, the antibody binds the same epitope as a referenceantibody comprising a VH region comprising the sequence of SEQ ID NO:56and a VL region comprising the sequence of SEQ ID NO:60 (098).

In one embodiment, the antibody binds the same epitope as a referenceantibody comprising a VH region comprising the sequence of SEQ ID NO:63and a VL region comprising the sequence of SEQ ID NO:67 (153).

In one embodiment, the antibody binds the same epitope as a referenceantibody comprising a VH region comprising the sequence of SEQ ID NO:70and a VL region comprising the sequence of SEQ ID NO:74 (132).

In one embodiment, the antibody binds to the same epitope as a referenceantibody comprising VH and VL regions selected from the group consistingof:

-   -   k) a VH region comprising the sequence of SEQ ID NO: 109 and a        VL region comprising the sequence of SEQ ID NO:110 (105);    -   l) a VH region comprising the sequence of SEQ ID NO: 111 and a        VL region comprising the sequence of SEQ ID NO:112 (100);    -   m) a VH region comprising the sequence of SEQ ID NO:113 and a VL        region comprising the sequence of SEQ ID NO:114 (125);    -   n) a VH region comprising the sequence of SEQ ID NO: 115 and a        VL region comprising the sequence of SEQ ID NO:116 (162);    -   o) a VH region comprising the sequence of SEQ ID NO:117 and a VL        region comprising the sequence of SEQ ID NO:118 (033);    -   p) a VH region comprising the sequence of SEQ ID NO:119 and a VL        region comprising the sequence of SEQ ID NO: 120 (160)    -   q) a VH region comprising the sequence of SEQ ID NO: 121 and a        VL region comprising the sequence of SEQ ID NO: 122 (166);    -   r) a VH region comprising the sequence of SEQ ID NO: 123 and a        VL region comprising the sequence of SEQ ID NO: 124 (152); and    -   s) a VH region comprising the sequence of SEQ ID NO: 125 and a        VL region comprising the sequence of SEQ ID NO: 126 (167).

In another additional or alternative aspect of the antibody of theinvention, the antibody binds to HER2 and comprises a VH CDR3, VH regionand/or VL region sequence similar or identical to a sequence of thenovel antibodies described herein.

In one embodiment, the antibody comprises a VH CDR3 region having asequence selected from the group consisting of

SEQ ID NO: 148, such as the sequence of SEQ ID NO:48 (127), optionallywherein the VH region is derived from the IgHV5-51-01 germline sequence;

SEQ ID NO:52 (159), optionally wherein the VH region is derived from theIgHV5-51-01 germline sequence;

SEQ ID NO:145, such as the sequence of SEQ ID NO:59 (098), optionallywherein the VH region is derived from the IgHV3-23-01 germline sequence;

SEQ ID NO: 154, such as the sequence of SEQ ID NO:66 (153), optionallywherein the VH region is derived from the IgHV3-30-03-01 germlinesequence; and

SEQ ID NO: 151, such as the sequence of SEQ ID NO:73 (132), optionallywherein the VH region is derived from the IgHV1-18-01 germline sequence.

In one embodiment, the antibody comprises a VH CDR3 region of one ofantibodies 105, 100, 125 or 162 as shown in FIG. 1, optionally whereinthe VH region is derived from an IgHV3-23-1 germline.

In one embodiment, the antibody comprises a VH CDR3 region of one ofantibodies 033, 160, 166, 152 or 167 as shown in FIG. 1, optionallywherein the VH region is derived from an IgHV3-30-3-01 germline.

In one embodiment, the antibody comprises a VH region selected from thegroup consisting of

-   -   a) a VH region comprising the CDR1, CDR2 and CDR3 sequences of        SEQ ID NOs:146, 147 and 148, such as the CDR1, CDR2 and CDR3        sequences of SEQ ID NOS: 43, 44 and 45 (127); optionally where        the VH region is derived from an IgHV5-51-01 germline;    -   b) a VH region comprising the CDR1, CDR2 and CDR3 sequences of        SEQ ID NOs:149, 51 and 52, such as the CDR1, CDR2 and CDR3        sequences of SEQ ID NOs:50, 51 and 52, respectively (159),        optionally where the VH region is derived from an IgHV5-51-01        germline;    -   c) a VH region comprising the CDR1, CDR2, and CDR3 sequences of        SEQ ID NOs:143, 144 and 145, such as the CRD1, CDR2, and CDR3        sequences of SEQ ID NOs: 57, 58 and 59 (098), respectively,        optionally where the VH region is derived from an IgHV3-23-01        germline;    -   d) a VH region comprising the CDR1, CDR2 and CDR3 sequences of        SEQ ID NOs:152, 153 and 154, such as the CDR1, CDR2 and CDR3        sequences of SEQ ID NOs:64, 65 and 66, respectively (153),        optionally where the VH region is derived from an IgHV3-30-03-01        germline; and    -   e) a VH region comprising the CDR1, CDR2, and CDR3 sequences of        SEQ ID NOs:71, 150 and 151, such as the CRD1, CDR2, and CDR3        sequences of SEQ ID NOs: 71, 72 and 73 (132), respectively,        optionally where the VH region is derived from an IgHV1-18-01        germline.

In one embodiment, the antibody comprises a VH region selected from thepreceding embodiment (a) and a VL region comprising the CDR1, CDR2, andCDR3 sequences of SEQ ID NO:47, AAS and SEQ ID NO:48, respectively(127); respectively, optionally where the VL region is derived from anIgKV1D-8-01 germline.

In one embodiment, the antibody comprises a VH region selected from thepreceding embodiment (b) and a VL region comprising the CDR1, CDR2, andCDR3 sequences of SEQ ID NO:54, AAS, and SEQ ID No:55 (159);respectively, optionally where the VL region is derived from anIgKV1D-16-01 germline.

In one embodiment, the antibody comprises a VH region which is thepreceding embodiment (c) and a VL region comprising the CDR1, CDR2, andCDR3 sequences of SEQ ID NO: 159, AAS and SEQ ID NO: 160, respectively,such as the VL CDR1, CDR2 and CDR3 sequences of SEQ ID NOS: 61, AAS andSEQ ID NO:62 (098), optionally wherein the VL region is derived fromIgKV1D-16-01.

In one embodiment, the antibody comprises a VH region which is thepreceding embodiment (d) and a VL region comprising the CDR1, CDR2, andCDR3 sequences of SEQ ID NO: 161, XAS (wherein X=D or A, preferably D),and SEQ ID NO: 162 (153), respectively, such as the VL CDR sequences ofSEQ ID NO:68, DAS, and 69, optionally wherein the VL region is derivedfrom IgKV1D-16-01.

In one embodiment, the antibody comprises a VH region which is thepreceding embodiment (e) and a VL region comprising the CDR1, CDR2, andCDR3 sequences of SEQ ID NO:75, DAS and SEQ ID NO:76 (132),respectively, optionally wherein the VL region is derived fromIgKV3-11-01.

In one embodiment, the antibody comprises a VH region comprising theCDR1, CDR2 and CDR3 sequences of SEQ ID NOs:43, 44 and 45, respectively;and a VL region comprising the CDR1, CDR2 and CDR3 sequences of SEQ IDNOs:47, AAS, and SEQ ID NO:48, respectively (127).

In one embodiment, the antibody comprises a VH region comprising theCDR1, CDR2 and CDR3 sequences of SEQ ID NOs:50, 51 and 52, respectively;and a VL region comprising the CDR1, CDR2 and CDR3 sequences of SEQ IDNOs:54, AAS, and SEQ ID NO:55, respectively (159).

In one embodiment, the antibody comprises a VH region comprising theCDR1, CDR2 and CDR3 sequences of SEQ ID NOs:57, 58 and 59, respectively;and a VL region comprising the CDR1, CDR2 and CDR3 sequences of SEQ IDNOs:60, AAS, and SEQ ID NO:61, respectively (098).

In one embodiment, the antibody comprises a VH region comprising theCDR1, CDR2 and CDR3 sequences of SEQ ID NOs:64, 65 and 66, respectively;and a VL region comprising the CDR1, CDR2 and CDR3 sequences of SEQ IDNOs:68, DAS, and SEQ ID NO:69, respectively (153).

In one embodiment, the antibody comprises a VH region comprising theCDR1, CDR2 and CDR3 sequences of SEQ ID NOs:71, 72 and 73, respectively;and a VL region comprising the CDR1, CDR2 and CDR3 sequences of SEQ IDNOs:75, DAS, and SEQ ID NO:76, respectively (132).

In separate embodiments, the antibody comprises:

-   -   a) a VH region comprising the sequence of SEQ ID NO:46 and,        preferably, a VL region comprising the sequence of SEQ ID NO:49        (127);    -   b) a VH region comprising the sequence of SEQ ID NO:49 and,        preferably, a VL region comprising the sequence of SEQ ID NO:53        (159);    -   c) a VH region comprising the sequence of SEQ ID NO:56 and,        preferably, a VL region comprising the sequence of SEQ ID NO:60        (098);    -   d) a VH region comprising the sequence of SEQ ID NO:63 an,        preferably, a VL region comprising the sequence of SEQ ID NO:67        (153);    -   e) a VH region comprising the sequence of SEQ ID NO:70 and,        preferably, a VL region comprising the sequence of SEQ ID NO:74        (132);    -   f) a VH region comprising the sequence of SEQ ID NO: 109 and,        preferably, a VL region comprising the sequence of SEQ ID NO:110        (105);    -   g) a VH region comprising the sequence of SEQ ID NO: 111 and,        preferably, a VL region comprising the sequence of SEQ ID NO:112        (100);    -   h) a VH region comprising the sequence of SEQ ID NO: 113 and,        preferably, a VL region comprising the sequence of SEQ ID NO:114        (125);    -   i) a VH region comprising the sequence of SEQ ID NO: 115 and,        preferably, a VL region comprising the sequence of SEQ ID NO:116        (162);    -   j) a VH region comprising the sequence of SEQ ID NO: 117 and,        preferably, a VL region comprising the sequence of SEQ ID NO:118        (033);    -   k) a VH region comprising the sequence of SEQ ID NO:119 and,        preferably, a VL region comprising the sequence of SEQ ID NO:        120 (160)    -   l) a VH region comprising the sequence of SEQ ID NO: 121 and,        preferably, a VL region comprising the sequence of SEQ ID NO:        122 (166);    -   m) a VH region comprising the sequence of SEQ ID NO: 123 and,        preferably, a VL region comprising the sequence of SEQ ID NO:        124 (152);    -   o) a VH region comprising the sequence of SEQ ID NO: 125 and,        preferably, a VL region comprising the sequence of SEQ ID NO:        126 (167); and/or    -   p) a variant of any of said antibodies, wherein said variant        preferably has at most 1, 2 or 3 amino-acid modifications, more        preferably amino-acid substitutions, such as conservative amino        acid substitutions and substitutions where the new amino acid is        one at the same position in an aligned sequence in FIG. 1 or 2,        particularly at positions indicated by “X” in the corresponding        consensus sequence.

Bispecific Antibodies

In one embodiment, the antibody is a bispecific antibody, comprising (i)a first antibody comprising antigen-binding region of an antibody asdefined herein, e.g. an antibody of cross-block 1, 2 or 3, or the VH andVL region comprising the sequences of (005), and (ii) a second antibodycomprising an antigen-binding region of an antibody which binds to CD3.

In one embodiment, the antibody is a bispecific antibody, comprising (i)a first antibody comprising an antigen-binding region of an antibody asdefined herein or the VH and VL region comprising the sequences of(005), and (ii) a second antibody comprising antigen-binding region ofan antibody as defined herein or the VH and VL region comprisingsequences of (005), wherein the first antigen-binding region binds to adifferent epitope than the second antigen-binding region.

In one embodiment the first antibody comprises a VH region comprising aCDR3 sequence of an antibody of cross-block 1, 2 or 3 as defined herein,such as SEQ ID NO: 4, 25 or 66 (169, 025 or 153), or a CDR3 sequence ofSEQ ID NO: 168 (005).

In one embodiment the first antibody comprises a VH region comprisingCDR1, CDR2 and CDR3 sequences of an antibody of cross-block 1, 2 or 3 asdefined herein, such as CDR1, CDR2, and CDR3 sequences SEQ ID NOs: 2, 3and 4 (169), or CDR1, CDR2 and CDR3 sequences of SEQ ID NOs:23, 24 and25 (025), or CDR1, CDR2 and CDR3 sequences of SEQ ID NOs: 64, 65 and 66(153), or CDR1, CDR2 CDR3 sequence of SEQ ID NOs: 166, 167 and 168(005).

In a further or alternative embodiment the first antibody comprises a VHregion comprising a CDR3 sequence of an antibody of cross-block 1, 2 or3 as defined herein, such as CDR3 sequence an antibody of cross-block 1of SEQ ID NO: 11 (050), or SEQ ID NO: 18 (084); or a CDR3 sequence of anantibody of cross-block 2 of SEQ ID NO: 31 (091), or SEQ ID NO: 38(129), or a CDR3 sequence of an antibody of cross-block 3 of SEQ ID NO:45 (127), or SEQ ID NO:52 (159), or SEQ ID NO:59 (098), or SEQ ID NO:73(132).

In one embodiment the first antibody comprises a VH region comprisingCDR1, CDR2 and CDR3 sequences of an antibody of cross-block 1, 2 or 3 asdefined herein, such as CDR1, CDR2, and CDR3 sequences SEQ ID NOs: 2, 3and 4 (169), or CDR1, CDR2 and CDR3 sequences of SEQ ID NOs:23, 24 and25 (025), or CDR1, CDR2 and CDR3 sequences of SEQ ID NOs: 64, 65 and 66(153), or CDR1, CDR2 CDR3 sequence of SEQ ID NOs: 166, 167 and 168(005).

In one embodiment the first antibody comprises a VH region comprisingCDR1, CDR2 and CDR3 sequences of an antibody of cross-block 1, 2 or 3 asdefined herein a VL region comprising CDR1, CDR2 and CDR3 sequences ofan antibody of cross-block 1, 2 or 3 as defined herein.

In a further or alternative embodiment the first antibody comprises a VHregion comprising CDR1, CDR2 and CDR3 sequences of an antibody ofcross-block 1, 2 or 3 as defined herein, such as CDR1, CDR2, and CDR3sequences of an antibody of cross-block 1 of SEQ ID NOs: 9, 10 and 11(050), or SEQ ID NOs: 16, 17 and 18 (084); or CDR1, CDR2, and CDR3sequences of an antibody of cross-block 2 of SEQ ID NOs: 30, 163 and 31(091), or SEQ ID NOs: 36, 37 and 38 (129), or CDR1, CDR2, and CDR3sequences of an antibody of cross-block 3 SEQ ID NOs: 43, 44 and 45(127), or SEQ ID NOs:50, 51 and 52 (159), or SEQ ID NOs:57, 58 and 59(098), or SEQ ID NOs:71, 72 and 73 (132).

In one embodiment the first antibody comprises a VH region and a VLregion selected from the group consisting of:

-   -   a) a VH region comprising the CDR1, CDR2, and CDR3 sequences of        SEQ ID NOs: 2, 3 and 4; and a VL region comprising the CDR1,        CDR2 and CDR3 sequences of SEQ ID: 6, GAS and SEQ ID NO:7,        respectively (169);    -   b) a VH region comprising the CDR1, CDR2, and CDR3 sequences of        SEQ ID NOs: 23, 24 and 25; and a VL region comprising the CDR1,        CDR2 and CDR3 sequences of SEQ ID NO: 27, AAS and SEQ ID NO:28,        respectively (025);    -   c) a VH region comprising the CDR1, CDR2 and CDR3 sequences of        SEQ ID NOs:64, 65 and 66; and a VL region comprising the CDR1,        CDR2 and CDR3 sequences of SEQ ID NO: 68, DAS and SEQ ID NO:69        (153); and    -   d) a VH region comprising the CDR1, CDR2 and CDR3 sequences of        SEQ ID NOs:166, 167 and 168; and a VL region comprising the        CDR1, CDR2 and CDR3 sequences of SEQ ID NO: 169, GAS and SEQ ID        NO: 170 (005).

In a further or alternative embodiment the first antibody comprises a VHregion and a VL region selected from the group consisting of:

-   -   a) a VH region comprising the CDR1, CDR2 and CDR3 sequences of        SEQ ID NOs:9, 127 and 11, such as the CDR1, CDR2 and CDR3        sequences of SEQ ID NOS: 9, 10 and 11 (050); optionally where        the VH region is derived from an IgHV3-23-1 germline;    -   b) a VH region comprising the CDR1, CDR2 and CDR3 sequences of        SEQ ID NOs:128, 129 and 130, such the CDR1, CDR2 and CDR3        sequences of SEQ ID NOs:16, 17 and 18, respectively (084),        optionally where the VH region is derived from an IgHV1-69-04        germline; and    -   c) a VH region comprising the CDR1, CDR2 and CDR3 sequences of        SEQ ID NOs:137, 138 and 139, such the CDR1, CDR2 and CDR3        sequences of SEQ ID NOs:30, 163, and 31, respectively (091),        optionally where the VH region is derived from an IgHV4-34-01        germline; and    -   d) a VH region comprising the CDR1, CDR2, and CDR3 sequences of        SEQ ID NOs:140, 141 and 142, such as the CRD1, CDR2, and CDR3        sequences of SEQ ID NOs: 36, 37 and 38 (129), respectively,        optionally where the VH region is derived from an IgHV3-30-01        germline.    -   e) a VH region comprising the CDR1, CDR2 and CDR3 sequences of        SEQ ID NOs:146, 147 and 148, such as the CDR1, CDR2 and CDR3        sequences of SEQ ID NOS: 43, 44 and 45 (127); optionally where        the VH region is derived from an IgHV5-51-01 germline;    -   f) a VH region comprising the CDR1, CDR2 and CDR3 sequences of        SEQ ID NOs:149, 51 and 52, such as the CDR1, CDR2 and CDR3        sequences of SEQ ID NOs:50, 51 and 52, respectively (159),        optionally where the VH region is derived from an IgHV5-51-01        germline;    -   g) a VH region comprising the CDR1, CDR2, and CDR3 sequences of        SEQ ID NOs:143, 144 and 145, such as the CRD1, CDR2, and CDR3        sequences of SEQ ID NOs: 57, 58 and 59 (098), respectively,        optionally where the VH region is derived from an IgHV3-23-01        germline;    -   h) a VH region comprising the CDR1, CDR2, and CDR3 sequences of        SEQ ID NOs:71, 150 and 151, such as the CRD1, CDR2, and CDR3        sequences of SEQ ID NOs: 71, 72 and 73 (132), respectively,        optionally where the VH region is derived from an IgHV1-18-01        germline.

In one embodiment the second antibody is one of the previous embodimentdescribed for the first antibody, but wherein the second antibody bindsto a different epitope than the first antibody.

In one embodiment the second antibody is a CD3 antibody. In oneembodiment a CD3 antibody may be an antibody comprising a VH regioncomprising the sequence of SEQ ID NO: 171 (YTH12.5) and VL regioncomprising the sequence of SEQ ID NO:172 (YTH12.5). Another example of aCD3 antibody is an antibody comprising a VH region comprising thesequence of SEQ ID NO: 173 (huCLB-T3/4) and VL region comprising thesequence of SEQ ID NO: 174 (huCLB-T3/4).

In one embodiment, the antibody is a bispecific antibody, comprising (i)a first antibody having an Fc region and VH and VL sequences, whichantibody comprises the VH and VL region sequences of (005), (025), (153)or (169), and which antibody comprises an IgG1 wildtype Fc region,wherein the CH3 region contains Ile at position 350, a Thr at position370, and a Leu at position 405 and (ii) a second antibody having an Fcregion and VH and VL sequences, which antibody comprising the VH and VLregion sequences of (005), (025), (153) or (169), and which antibodycomprises a IgG1 wildtype Fc region, wherein the CH3 region contains anArg at position 409. Specific embodiments are disclosed in examples.

In one embodiment, the antibody is a bispecific antibody, comprising (i)a first antibody having an Fc region and VH and VL sequences, whereinthe VH region comprises the amino acid sequence of SEQ ID NO: 164, andthe VL region comprises the amino acid sequence of SEQ ID NO: 165 (005),optionally wherein the first antibody comprises an IgG1,κ Fc region,wherein the CH3 region contains Ile at position 350, a Thr at position370, and a Leu at position 405; and (ii) a second antibody having an Fcregion and VH and VL sequences, wherein the VH region comprises theamino acid sequence of SEQ ID NO:1 and the VL region comprises the aminoacid sequence of SEQ ID NO:5 (169), optionally wherein the secondantibody comprises an IgG1,κ Fc region having an Arg at position 409.

In one embodiment, the antibody is a bispecific antibody, comprising (i)a first antibody having an Fc region and VH and VL sequences, whereinthe VH region comprises the amino acid sequence of SEQ ID NO:22, and theVL region comprises the amino acid sequence of SEQ ID NO:26 (025),optionally wherein the first antibody comprises an IgG1,κ Fc region,wherein the CH3 region contains Ile at position 350, a Thr at position370, and a Leu at position 405; and (ii) a second antibody having an Fcregion and VH and VL sequences, wherein the VH region comprises theamino acid sequence of SEQ ID NO: 164 and the VL region comprises theamino acid sequence of SEQ ID NO:165 (005), optionally wherein thesecond antibody comprises an IgG1,κ Fc region having an Arg at position409.

In one embodiment, the antibody is a bispecific antibody, comprising (i)a first antibody having an Fc region and VH and VL sequences, whereinthe VH region comprises the amino acid sequence of SEQ ID NO:22, and theVL region comprises the amino acid sequence of SEQ ID NO:26 (025),optionally wherein the first antibody comprises an IgG1,κ Fc region,wherein the CH3 region contains Ile at position 350, a Thr at position370, and a Leu at position 405; and (ii) a second antibody having an Fcregion and VH and VL sequences, wherein the VH region comprises theamino acid sequence of SEQ ID NO:63 and the VL region comprises theamino acid sequence of SEQ ID NO:37 (153), optionally wherein the secondantibody comprises an IgG1,κ Fc region having an Arg at position 409.

In one embodiment, the antibody is a bispecific antibody, comprising (i)a first antibody having an Fc region and VH and VL sequences, whereinthe VH region comprises the amino acid sequence of SEQ ID NO:22, and theVL region comprises the amino acid sequence of SEQ ID NO:26 (025),optionally wherein the first antibody comprises an IgG1,κ Fc region,wherein the CH3 region contains Ile at position 350, a Thr at position370, and a Leu at position 405; and (ii) a second antibody having an Fcregion and VH and VL sequences, wherein the VH region comprises theamino acid sequence of SEQ ID NO:1 and the VL region comprises the aminoacid sequence of SEQ ID NO:5 (169), optionally wherein the secondantibody comprises an IgG1,κ Fc region having an Arg at position 409.

In one embodiment, the antibody is a bispecific antibody, comprising (i)a first antibody having an Fc region and VH and VL sequences, whereinthe VH region comprises the amino acid sequence of SEQ ID NO:63, and theVL region comprises the amino acid sequence of SEQ ID NO:67 (153),optionally wherein the first antibody comprises an IgG1,κ Fc region,wherein the CH3 region contains Ile at position 350, a Thr at position370, and a Leu at position 405; and (ii) a second antibody having an Fcregion and VH and VL sequences, wherein the VH region comprises theamino acid sequence of SEQ ID NO: 164 and the VL region comprises theamino acid sequence of SEQ ID NO:165 (005), optionally wherein thesecond antibody comprises an IgG1,κ Fc region having an Arg at position409.

In one embodiment, the antibody is a bispecific antibody, comprising (i)a first antibody having an Fc region and VH and VL sequences, whereinthe VH region comprises the amino acid sequence of SEQ ID NO:63, and theVL region comprises the amino acid sequence of SEQ ID NO:67 (153),optionally wherein the first antibody comprises an IgG1,κ Fc region,wherein the CH3 region contains Ile at position 350, a Thr at position370, and a Leu at position 405; and (ii) a second antibody having an Fcregion and VH and VL sequences, wherein the VH region comprises theamino acid sequence of SEQ ID NO:1 and the VL region comprises the aminoacid sequence of SEQ ID NO:5 (169), optionally wherein the secondantibody comprises an IgG1,κ Fc region having an Arg at position 409.

In one embodiment, the antibody is a bispecific antibody, comprising (i)a first antibody having an Fc region and VH and VL sequences, whereinthe VH region comprises the amino acid sequence of SEQ ID NO:63, and theVL region comprises the amino acid sequence of SEQ ID NO:67 (153),optionally wherein the first antibody comprises an IgG1,κ Fc regionhaving Arg at position 409, or Gln at position 297, or Arg at position409 and Gln at position 297; and (ii) a second antibody having an Fcregion and VH and VL sequences, wherein the VH region comprises theamino acid sequence of SEQ ID NO: 171 and the VL region comprises theamino acid sequence of SEQ ID NO: 172 (YTH12.5), optionally wherein thesecond antibody comprises an IgG1,κ Fc region having an Gln at position297, or Leu at position 405, or Gln at position 297 and Leu at position405.

In one embodiment, the antibody is a bispecific antibody, comprising (i)a first antibody having an Fc region and VH and VL sequences, whereinthe VH region comprises the amino acid sequence of SEQ ID NO: 1, and theVL region comprises the amino acid sequence of SEQ ID NO:5 (169),optionally wherein the first antibody comprises an IgG1,κ Fc regionhaving Arg at position 409; and (ii) a second antibody having an Fcregion and VH and VL sequences, wherein the VH region comprises theamino acid sequence of SEQ ID NO: 171 and the VL region comprises theamino acid sequence of SEQ ID NO: 172 (YTH12.5), optionally wherein thesecond antibody comprises an IgG1,κ Fc region having an Gln at position297, or Leu at position 405, or Gln at position 297 and Leu at position405.

In one embodiment, the antibody is a bispecific antibody, comprising (i)a first antibody having an Fc region and VH and VL sequences, whereinthe VH region comprises the amino acid sequence of SEQ ID NO:63, and theVL region comprises the amino acid sequence of SEQ ID NO:67 (153),optionally wherein the first antibody comprises an IgG1,κ Fc regionhaving Arg at position 409, or Gln at position 297, or Arg at position409 and Gln at position 297; and (ii) a second antibody having an Fcregion and VH and VL sequences, wherein the VH region comprises theamino acid sequence of SEQ ID NO: 173 and the VL region comprises theamino acid sequence of SEQ ID NO: 174 (huCLB-T3/4), optionally whereinthe second antibody comprises an IgG1,κ Fc region having an Gln atposition 297, or Leu at position 405, or Gln at position 297 and Leu atposition 405.

In one embodiment, the antibody is a bispecific antibody, comprising (i)a first antibody having an Fc region and VH and VL sequences, whereinthe VH region comprises the amino acid sequence of SEQ ID NO: 1, and theVL region comprises the amino acid sequence of SEQ ID NO:5 (169),optionally wherein the first antibody comprises an IgG1,κ Fc regionhaving Arg at position 409; and (ii) a second antibody having an Fcregion and VH and VL sequences, wherein the VH region comprises theamino acid sequence of SEQ ID NO: 173 and the VL region comprises theamino acid sequence of SEQ ID NO: 174 (huCLB-T3/4), optionally whereinthe second antibody comprises an IgG1,κ Fc region having an Gln atposition 297, or Leu at position 405, or Gln at position 297 and Leu atposition 405.

A CD3 antibody is an antibody with a VH region comprising the sequenceof SEQ ID NO: 171 (VH YTH12.5) and VL region comprising the sequence ofSEQ ID NO: 172 (VL YTH12.5). Another example is a CD3 antibody with a VHregion comprising the sequence of SEQ ID NO: 173 (VH huCLB-T3/4) and VLregion comprising the sequence of SEQ ID NO:174 (VL huCLB-T3/4).

In one embodiment a bispecific antibody of the present invention may beselected from the group consisting of: IgG1-005-ITL×IgG1-169-K409R,IgG1-025-ITL×IgG1-005-K409R, IgG1-025-ITL×IgG1-153-K409R,IgG1-025-ITL×IgG1-169-K409R, IgG1-153-ITL×IgG1-005-K409R; andIgG1-153-ITL×IgG1-169-K409R, wherein IgG1-005-ITL means 005 IgG1,κhaving Ile at position 350, Thr at position 370, and Leu at position405, IgG1-005-K409R means 005 IgG1,κ having an Arg at position 409,IgG1-025-ITL means 025 IgG1,κ having Ile at position 350, Thr atposition 370, and Leu at position 405, IgG1-153-ITL means 153 IgG1,κhaving contains Ile at position 350, Thr at position 370, and Leu atposition 405, IgG1-153-K409R means 153 IgG1,κ having an Arg at position409, IgG1-169-K409R means 169 IgG1,κ having an Arg at position 409, andwherein the bold numbers refer to antibodies described herein with theVH and VL regions comprising the sequences described in table 1 and for005 in example 21; i.e. SEQ ID NOs:164 and 165.

In one embodiment the bispecific antibody may be selected from the groupconsisting of: IgG1-HER2-153-K409R×IgG1-YTH12.5-F405L,IgG1-HER2-153-K409R×IgG1-YTH12.5-N297Q-F405L,IgG1-HER2-153-K409R×IgG1-hu-CLB-T3/4-F405L,IgG1-HER2-153-K409R×IgG1-hu-CLB-T3/4-N297Q-F405L,IgG1-HER2-153-N297Q-K409R×IgG1-YTH12.5-F405L,IgG1-HER2-153-N297Q-K409R×IgG1-YTH12.5-N297Q-F405L,IgG1-HER2-153-N297Q-K409R×IgG1-hu-CLB-T3/4-F405L,IgG1-HER2-153-N297Q-K409R×IgG1-hu-CLB-T3/4-N297Q-F405L,IgG1-HER2-169-K409R×IgG1-hu-CLB-T3/4-F405L,IgG1-HER2-169-K409R×IgG1-hu-CLB-T3/4-N297Q-F405L,IgG1-HER2-169-K409R×IgG1-YTH12.5-F405L andIgG1-HER2-169-K409R×IgG1-YTH12.5-N297Q-F405L.

Functional Properties of Group 1, 2 and 3 Antibodies and BispecificAntibodies

In another aspect of the antibody of the invention, the antibody bindsto the same HER2 epitope as one or more of the novel Group 1, 2 or 3antibodies described herein, preferably when determined as described inExample 14; and is further characterized by one or more propertiesdetermined as described in Examples 12, 13, 15, 16, 17, 18 and 19.

In one embodiment, the HER2 antibody has a lower EC₅₀ value (halfmaximal effective concentration) than trastuzumab in binding to A431cells, preferably an EC₅₀ value lower than 0.80 μg/ml, 0.50 μg/ml, or0.30 μg/ml, when determined as described in Example 12, and preferablybinds the same epitope as at least one reference antibody comprising theVH and VL regions selected from the group consisting of

-   -   a) a VH region comprising the sequence of SEQ ID NO:1 and a VL        region comprising the sequence of SEQ ID NO:5 (169);    -   b) a VH region comprising the sequence of SEQ ID NO: 15 and a VL        region comprising the sequence of SEQ ID NO: 19 (084);    -   c) a VH region comprising the sequence of SEQ ID NO:22 and a VL        region comprising the sequence of SEQ ID NO:26 (025);    -   d) a VH region comprising the sequence of SEQ ID NO:29 and a VL        region comprising the sequence of SEQ ID NO:32 (091);    -   e) a VH region comprising the sequence of SEQ ID NO:46 and a VL        region comprising the sequence of SEQ ID NO:49 (127);    -   f) a VH region comprising the sequence of SEQ ID NO:49 and a VL        region comprising the sequence of SEQ ID NO:53 (159);    -   g) a VH region comprising the sequence of SEQ ID NO:56 and a VL        region comprising the sequence of SEQ ID NO:60 (098);    -   h) a VH region comprising the sequence of SEQ ID NO:63 and a VL        region comprising the sequence of SEQ ID NO:67 (153); and    -   i) a VH region comprising the sequence of SEQ ID NO:70 and a VL        region comprising the sequence of SEQ ID NO:74 (132).

In an additional or alternative embodiment, the anti-HER2 antibodyspecifically binds HER2-positive Rhesus epithelial cells, whendetermined as described in Example 13, and preferably binds the sameepitope as at least one reference antibody comprising the VH and VLregions selected from the group consisting of the VH and VL regions ofany of antibodies 169, 050, 084, 025, 091, 129, 127, 159, 098, 153 and132.

In an additional or alternative embodiment, the anti-HER2 antibodyefficiently induces ADCC (antibody-dependent cell-mediatedcytotoxicity), preferably achieving a specific ⁵¹Cr-release of at least30%, more preferably at least 40%, when determined as described inExample 15, and preferably binds the same epitope as at least onereference antibody comprising the VH and VL regions selected from thegroup consisting of:

-   -   a) a VH region comprising the sequence of SEQ ID NO:1 and a VL        region comprising the sequence of SEQ ID NO:5 (169);    -   b) a VH region comprising the sequence of SEQ ID NO:8 and a VL        region comprising the sequence of SEQ ID NO: 12 (050);    -   c) a VH region comprising the sequence of SEQ ID NO: 15 and a VL        region comprising the sequence of SEQ ID NO: 19 (084);    -   d) a VH region comprising the sequence of SEQ ID NO:22 and a VL        region comprising the sequence of SEQ ID NO:26 (025);    -   e) a VH region comprising the sequence of SEQ ID NO:29 and a VL        region comprising the sequence of SEQ ID NO:32 (091);    -   f) a VH region comprising the sequence of SEQ ID NO:35 and a VL        region comprising the sequence of SEQ ID NO:39 (129); and    -   g) a VH region comprising the sequence of SEQ ID NO:63 an,        preferably, a VL region comprising the sequence of SEQ ID NO:67        (153).

In an additional or alternative embodiment, the HER2 antibodyspecifically binds HER2-expressing AU565 cells but promotesligand-independent proliferation of the cells less than any of F5 and C1when determined as described in Example 16, and preferably binds thesame epitope as at least one reference antibody comprising the VH and VLregions selected from the group consisting of

-   -   a) a VH region comprising the sequence of SEQ ID NO:1 and a VL        region comprising the sequence of SEQ ID NO:5 (169);    -   b) a VH region comprising the sequence of SEQ ID NO:8 and a VL        region comprising the sequence of SEQ ID NO: 12 (050);    -   c) a VH region comprising the sequence of SEQ ID NO: 15 and a VL        region comprising the sequence of SEQ ID NO: 19 (084);    -   d) a VH region comprising the sequence of SEQ ID NO:22 and a VL        region comprising the sequence of SEQ ID NO:26 (025);    -   e) a VH region comprising the sequence of SEQ ID NO:29 and a VL        region comprising the sequence of SEQ ID NO:32 (091);    -   f) a VH region comprising the sequence of SEQ ID NO:35 and a VL        region comprising the sequence of SEQ ID NO:39 (129);    -   g) a VH region comprising the sequence of SEQ ID NO:46 and a VL        region comprising the sequence of SEQ ID NO:49 (127);    -   h) a VH region comprising the sequence of SEQ ID NO:49 and a VL        region comprising the sequence of SEQ ID NO:53 (159);    -   i) a VH region comprising the sequence of SEQ ID NO:56 and a VL        region comprising the sequence of SEQ ID NO:60 (098);    -   j) a VH region comprising the sequence of SEQ ID NO:63 and a VL        region comprising the sequence of SEQ ID NO:67 (153); and    -   k) a VH region comprising the sequence of SEQ ID NO:70 and a VL        region comprising the sequence of SEQ ID NO:74 (132).

In an additional or alternative embodiment, the HER2 antibodyspecifically binds HER2-expressing AU565 cells and inhibitsligand-independent proliferation of the cells, preferably inhibitingproliferation by at least 20%, more preferably at least 25%, whendetermined as described in Example 16, and preferably binds the sameepitope as at least one reference antibody comprising the VH and VLregions selected from the group consisting of:

-   -   a) a VH region comprising the sequence of SEQ ID NO:1 and a VL        region comprising the sequence of SEQ ID NO:5 (169); and    -   b) a VH region comprising the sequence of SEQ ID NO:8 and a VL        region comprising the sequence of SEQ ID NO: 12 (050).

In an additional or alternative embodiment, the HER2 antibodyspecifically binds HER2-expressing AU565 cells but has no significanteffect on, or does not promote, ligand-induced proliferation of thecells, preferably inhibiting proliferation by no more than 25%, morepreferably by no more than 15%, when determined as described in Example17, and binds the same epitope as at least one reference antibodycomprising the VH and VL regions selected from the group consisting of:

-   -   a) a VH region comprising the sequence of SEQ ID NO:1 and a VL        region comprising the sequence of SEQ ID NO:5 (169);    -   b) a VH region comprising the sequence of SEQ ID NO:8 and a VL        region comprising the sequence of SEQ ID NO: 12 (050);    -   c) a VH region comprising the sequence of SEQ ID NO: 15 and a VL        region comprising the sequence of SEQ ID NO: 19 (084); and    -   d) a VH region comprising the sequence of SEQ ID NO:56 and a VL        region comprising the sequence of SEQ ID NO:60 (098).

In an additional or alternative embodiment, the HER2 antibodyspecifically binds HER2-expressing MCF-7 cells and inhibitsligand-induced proliferation, e.g. it may completely inhibit theligand-induced effect or inhibit the total proliferation by 50%, e.g.60% or 70% or 80%, of the cells when determined as described in Example17, and binds the same epitope as at least one reference antibodycomprising the VH and VL regions selected from the group consisting of:

-   -   a) a VH region comprising the sequence of SEQ ID NO:22 and a VL        region comprising the sequence of SEQ ID NO:26 (025);    -   b) a VH region comprising the sequence of SEQ ID NO:29 and a VL        region comprising the sequence of SEQ ID NO:32 (091);    -   c) a VH region comprising the sequence of SEQ ID NO:35 and a VL        region comprising the sequence of SEQ ID NO:39 (129); and    -   d) a VH region comprising the sequence of SEQ ID NO:63 an,        preferably, a VL region comprising the sequence of SEQ ID NO:67        (153).

In an additional or alternative embodiment, the antibody, whenconjugated directly or indirectly to a therapeutic moiety such as atruncated form of the pseudomonas-exotoxin A, is more effective thantrastuzumab in killing AU565 cells, A431 cells, or both AU565 and A431cells, when determined as described in Example 18.

In one embodiment, the conjugated antibody has an EC₅₀ value of lessthan 70 ng/ml, less than 50 ng/ml, or less than 30 ng/ml in killingAU565 cells and/or A431 cells, when determined as described in Example18, and binds the same epitope as at least one reference antibodycomprising the VH and VL regions of an antibody selected from the groupconsisting of 169, 091, 050, 084, 098, 05, 153, 129, 132, 127 and 159;preferably selected from antibodies 153, 129, 098, 091 and 025.

In one embodiment, the conjugated antibody has or results in a higherpercentage of killed AU565 cells than trastuzumab and pertuzumab whendetermined as described in Example 18, preferably killing at least 49%,more preferably at least 60% of the AU565 cells, and binds the sameepitope as at least one reference antibody comprising the VH and VLregions of an antibody selected from the group consisting of 169, 091,050, 084, 098, 025, 153, 129, 132, 127 and 159; preferably selected fromantibodies 153, 132, 127, 129, 159 and 025.

In a preferred embodiment, the conjugated antibody binds to the sameepitope as a reference antibody comprising a VH region comprising thesequence of SEQ ID NO:49 and a VL region comprising the sequence of SEQID NO:53 (159).

In one embodiment, the conjugated antibody has a higher percentage ofkilled AU431 cells than trastuzumab and pertuzumab when determined asdescribed in Example 18, preferably killing at least 50%, morepreferably at least 70%, and binds the same epitope as at least onereference antibody comprising the VH and VL regions of an antibodyselected from the group consisting of 025, 084, 091, 098, 129 and 153;preferably selected from antibodies 025, 091, 098, 129 and 153.

In a preferred embodiment, the conjugated antibody binds to the sameepitope as a reference antibody comprising a VH region comprising thesequence of SEQ ID NO:56 and a VL region comprising the sequence of SEQID NO:60 (098).

In an additional or alternative embodiment, the antibody is internalizedby tumor cells expressing HER2, such as AU565 cells, to a higher degreethan trastuzumab and pertuzumab, preferably more than twice or threetimes the amount of internalized trastuzumab, preferably when determinedaccording to Example 18, and binds to the same epitope as an antibodycomprising VH and VL regions selected from the group consisting of:

-   -   a) a VH region comprising the sequence of SEQ ID NO:46 and a VL        region comprising the sequence of SEQ ID NO:49 (127);    -   b) a VH region comprising the sequence of SEQ ID NO:49 and a VL        region comprising the sequence of SEQ ID NO:53 (159);    -   c) a VH region comprising the sequence of SEQ ID NO:56 and a VL        region comprising the sequence of SEQ ID NO:60 (098);    -   d) a VH region comprising the sequence of SEQ ID NO:63 and a VL        region comprising the sequence of SEQ ID NO:67 (153); and    -   e) a VH region comprising the sequence of SEQ ID NO:70 and a VL        region comprising the sequence of SEQ ID NO:74 (132).

Preferably, the antibody binds to the same epitope as an antibodycomprising VH and VL regions selected from

-   -   a) a VH region comprising the sequence of SEQ ID NO:46 and a VL        region comprising the sequence of SEQ ID NO:49 (127) and    -   b) a VH region comprising the sequence of SEQ ID NO:56 and a VL        region comprising the sequence of SEQ ID NO:60 (098).

In a further embodiment, the antibody binds to Domain II or IV of HER2,preferably wherein the antibody does not significantly promoteproliferation of HER2 expressing cells, and is more efficientlyinternalized, or is internalized to a higher degree, than trastuzumab orpertuzumab into HER2-expressing tumor cells, preferably when determinedas described in the Examples, e.g. examples 16 and 19, respectively.

In a further embodiment the antibody enhanced HER2 downmodulation morethan trastuzumab, e.g. the antibody enhanced HER2 downmodulation by more30%, such as more than 40% or more than 50% when determined as describedin example 22, preferably wherein the antibody binds to the same epitopeas an antibody of cross-block group 3 of the present invention, e.g. anantibody binding to the same epitope as an antibody comprising VH and VLregions selected from the group consisting of:

-   -   a) a VH region comprising the sequence of SEQ ID NO:56 and a VL        region comprising the sequence of SEQ ID NO:60 (098);    -   b) a VH region comprising the sequence of SEQ ID NO:63 and a VL        region comprising the sequence of SEQ ID NO:67 (153).

In another or alternative embodiment the antibody decreased tumourgrowth and improved survival in vivo more than trastuzumab, whendetermined as described in example 29, preferably wherein the antibodybinds to the same epitope as an antibody of cross-block 1 or cross-block2 of the present invention, e.g. an antibody binding to the same epitopeas an antibody comprising VH and VL regions selected from the groupconsisting of:

-   -   a) a VH region comprising the sequence of SEQ ID NO:1 and a VL        region comprising the sequence of SEQ ID NO:5 (169);    -   b) a VH region comprising the sequence of SEQ ID NO: 15 and a VL        region comprising the sequence of SEQ ID NO: 19 (084); and    -   c) a VH region comprising the sequence of SEQ ID NO:29 and a VL        region comprising the sequence of SEQ ID NO:32 (091).

In another or alternative embodiment the antibody decreased tumourgrowth and improved survival in vivo more than trastuzumab, whendetermined as described in example 30, preferably wherein the antibodybinds to the same epitope as an antibody of cross-block 2 or cross-block3 of the present invention, e.g. an antibody binding to the same epitopeas an antibody comprising VH and VL regions selected from the groupconsisting of:

-   -   a) a VH region comprising the sequence of SEQ ID NO:22 and a VL        region comprising the sequence of SEQ ID NO:26 (025);    -   b) a VH region comprising the sequence of SEQ ID NO:29 and a VL        region comprising the sequence of SEQ ID NO:32 (091);    -   c) a VH region comprising the sequence of SEQ ID NO:35 and a VL        region comprising the sequence of SEQ ID NO:39 (129); and    -   d) a VH region comprising the sequence of SEQ ID NO:63 and a VL        region comprising the sequence of SEQ ID NO:67 (153).

More particularly, wherein the antibody binds to the same epitope as anantibody comprising VH and VL regions selected from the group consistingof:

-   -   a) a VH region comprising the sequence of SEQ ID NO:22 and a VL        region comprising the sequence of SEQ ID NO:26 (025); and    -   b) a VH region comprising the sequence of SEQ ID NO:29 and a VL        region comprising the sequence of SEQ ID NO:32 (091).

In one embodiment the antibody is a bispecific antibody.

In a further embodiment the antibody is a bispecific antibody whichenhanced HER2 downmodulation, in particular more than their monospecificcounterparts, e.g. the antibody enhanced HER2 downmodulation by more20%, such as more than 30% or more than 40% when determined as describedin example 22, preferably wherein the antibody binds to the sameepitopes as bispecific antibody selected from the group consisting ofIgG1-005-ITL×IgG1-169-K409R, IgG1-025-ITL×IgG1-005-K409R,IgG1-025-ITL×IgG1-153-K409R, IgG1-025-ITL×IgG1-169-K409R,IgG1-153-ITL×IgG1-005-K409R; and IgG1-153-ITL×IgG1-169-K409R.

In an additional or alternative embodiment, the bispecific antibodyspecifically binds HER2-expressing AU565 cells and inhibitsligand-induced proliferation of the cells when determined as describedin Example 24, and binds the same epitopes as at least one bispecificantibody selected from the group consisting of:IgG1-005-ITL×IgG1-169-K409R, IgG1-025-ITL×IgG1-005-K409R,IgG1-025-ITL×IgG1-153-K409R, IgG1-025-ITL×IgG1-169-K409R,IgG1-153-ITL×IgG1-005-K409R; and IgG1-153-ITL×IgG1-169-K409R. Inparticular the bispecific antibody inhibits proliferation of the AU565cells more than their monospecific counterparts and is selected from thegroup consisting of IgG1-005-ITL×IgG1-169-K409R andIgG1-025-ITL×IgG1-005-K409R.

In an additional or alternative embodiment the bispecific antibody is aHER2×CD3 bispecific antibody induce T cell mediated cytotoxicity ofAU565 as described in example 25, and binds the same epitopes as atleast one of the bispecific antibodies selected from the groupconsisting of: Duo huCLB-Q/153-Q, Duo huCLB-Q/B12-Q, Duo YTH12.5/153-Qand Duo YTH12.5/B12-Q (Duo indicating bispecific antibody).

Antibody Formats

The present invention provides HER2 antibodies which efficiently bind toand internalize into HER2-expressing tumor cells, typically withoutsignificantly promoting ligand-independent proliferation of the cells.Depending on the desired functional properties for a particular use,particular antibodies can be selected from the set of antibodiesprovided in the present invention and/or their format can be adapted tochange these properties, as described below.

The antibody of the invention can be of any isotype. The choice ofisotype typically will be guided by the desired effector functions, suchas ADCC induction. Exemplary isotypes are IgG1, IgG2, IgG3, and IgG4.Either of the human light chain constant regions, kappa or lambda, maybe used. If desired, the class of a HER2 antibody of the presentinvention may be switched by known methods. For example, an antibody ofthe present invention that was originally IgM may be class switched toan IgG antibody of the present invention. Further, class switchingtechniques may be used to convert one IgG subclass to another, forinstance from IgG1 to IgG2. Thus, the effector function of theantibodies of the present invention may be changed by isotype switchingto, e.g., an IgG1, IgG2, IgG3, IgG4, IgD, IgA, IgE, or IgM antibody forvarious therapeutic uses. In one embodiment an antibody of the presentinvention is an IgG1 antibody, for instance an IgG1,κ.

In a further embodiment, the antibody of the invention isglyco-engineered to reduce fucose and thus enhance ADCC, e.g. byaddition of compounds to the culture media during antibody production asdescribed in US2009317869 or as described in van Berkel et al. (2010)Biotechnol. Bioeng. 105:350 or by using FUT8 knockout cells, e.g. asdescribed in Yamane-Ohnuki et al (2004) Biotechnol. Bioeng 87:614. ADCCmay alternatively be optimized using the method described by Umaha etal. (1999) Nature Biotech 17:176.

In a further embodiment, the antibody of the invention has beenengineered to enhance complement activation, e.g. as described inNatsume et al. (2009) Cancer Sci. 100:2411.

In one embodiment, the antibody of the invention is a full-lengthantibody, preferably an IgG1 antibody, in particular an IgG1,κ antibody.In another embodiment, the antibody of the invention is an antibodyfragment or a single-chain antibody.

Antibody fragments may e.g. be obtained by fragmentation usingconventional techniques, and the fragments screened for utility in thesame manner as described herein for whole antibodies. For example,F(ab′)₂ fragments may be generated by treating an antibody with pepsin.The resulting F(ab′)₂ fragment may be treated to reduce disulfidebridges with a reducing agent, such as dithiothreitol, to produce Fab′fragments. Fab fragments may be obtained by treating an antibody withpapain. A F(ab′)₂ fragment may also be produced by binding Fab′fragments via a thioether bond or a disulfide bond. Antibody fragmentsmay also be generated by expression of nucleic acids encoding suchfragments in recombinant cells (see for instance Evans et al., J.Immunol. Meth. 184, 123-38 (1995)). For example, a chimeric geneencoding a portion of an F(ab′)₂ fragment could include DNA sequencesencoding the C_(H)1 domain and hinge region of the H chain, followed bya translational stop codon to yield such a truncated antibody fragmentmolecule.

As explained above, in one embodiment, the HER2 antibody of theinvention is a bivalent antibody, i.e. an antibody capable of bindingtwo antigens or epitopes on the same antigen.

In another embodiment, the HER2 antibody of the invention is amonovalent antibody.

In one embodiment, the antibody of the invention is a Fab fragment or aone-armed antibody, such as described in US20080063641 (Genentech) orother monovalent antibody, e.g. such as described in WO2007048037(Amgen).

In a preferred embodiment, a monovalent antibody has a structure asdescribed in WO2007059782 (Genmab) (incorporated herein by reference)having a deletion of the hinge region. Accordingly, in one embodiment,the antibody is a monovalent antibody, wherein said HER2 antibody isconstructed by a method comprising:

i) providing a nucleic acid construct encoding the light chain of saidmonovalent antibody, said construct comprising a nucleotide sequenceencoding the VL region of a selected antigen specific HER2 antibody anda nucleotide sequence encoding the constant CL region of an Ig, whereinsaid nucleotide sequence encoding the VL region of a selected antigenspecific antibody and said nucleotide sequence encoding the CL region ofan Ig are operably linked together, and wherein, in case of an IgG1subtype, the nucleotide sequence encoding the CL region has beenmodified such that the CL region does not contain any amino acidscapable of forming disulfide bonds or covalent bonds with other peptidescomprising an identical amino acid sequence of the CL region in thepresence of polyclonal human IgG or when administered to an animal orhuman being;

ii) providing a nucleic acid construct encoding the heavy chain of saidmonovalent antibody, said construct comprising a nucleotide sequenceencoding the VH region of a selected antigen specific antibody and anucleotide sequence encoding a constant CH region of a human Ig, whereinthe nucleotide sequence encoding the CH region has been modified suchthat the region corresponding to the hinge region and, as required bythe Ig subtype, other regions of the CH region, such as the CH3 region,does not comprise any amino acid residues which participate in theformation of disulphide bonds or covalent or stable non-covalentinter-heavy chain bonds with other peptides comprising an identicalamino acid sequence of the CH region of the human Ig in the presence ofpolyclonal human IgG or when administered to an animal human being,wherein said nucleotide sequence encoding the VH region of a selectedantigen specific antibody and said nucleotide sequence encoding the CHregion of said Ig are operably linked together;

iii) providing a cell expression system for producing said monovalentantibody;

iv) producing said monovalent antibody by co-expressing the nucleic acidconstructs of (i) and (ii) in cells of the cell expression system of(iii).

Similarly, in one embodiment, the HER2 antibody is a monovalentantibody, which comprises

(i) a variable region of an antibody of the invention as describedherein or an antigen binding part of the said region, and

(ii) a C_(H) region of an immunoglobulin or a fragment thereofcomprising the C_(H)2 and C_(H)3 regions, wherein the C_(H) region orfragment thereof has been modified such that the region corresponding tothe hinge region and, if the immunoglobulin is not an IgG4 subtype,other regions of the C_(H) region, such as the C_(H)3 region, do notcomprise any amino acid residues, which are capable of forming disulfidebonds with an identical C_(H) region or other covalent or stablenon-covalent inter-heavy chain bonds with an identical C_(H) region inthe presence of polyclonal human IgG.

In a further embodiment hereof, the heavy chain of the monovalent HER2antibody has been modified such that the entire hinge has been deleted.

In another further embodiment, the immunoglobulin referred to in stepii) above is of the IgG4 subtype.

In another further embodiment, said monovalent antibody is of the IgG4subtype, but the C_(H)3 region has been modified so that one or more ofthe following amino acid substitutions have been made:

Numbering of CH3 mutations EU index KABAT* G4* Mutations E378 E357 E357Aor E357T or E357V or E357I S387 S364 S364R or S364K T389 T366 T366A orT366R or T366K or T366N L391 L368 L368A or L368V or L368E or L368G orL368S or L368T D427 D399 D399A or D399T or D399S F436 F405 F405A orF405L or F405T or F405D or F405R or F405Q or F405K or F405Y Y438 Y407Y407A or Y407E or Y407Q or Y407K or Y407F F436 and F405 and (F405T andY407E) or (F405D and Y407E) Y438 Y407 D427 and D399 and (D399S andY407Q) or (D399S and Y407K) Y438 Y407 or (D399S and Y407E) *KABATindicates amino acid numbering according to Kabat (Kabat et al.,Sequences of Proteins of Immunological Interest, 5th Ed. Public HealthService, National Institutes of Health, Bethesda, MD. (1991). EU indexindicates amino acid numbering according to EU index as outlined inKabat et al., (supra).

In another further embodiment, the sequence of said monovalent antibodyhas been modified so that it does not comprise any acceptor sites forN-linked glycosylation. HER2 antibodies of the invention also includesingle chain antibodies. Single chain antibodies are peptides in whichthe heavy and light chain Fv regions are connected. In one embodiment,the present invention provides a single-chain Fv (scFv) wherein theheavy and light chains in the Fv of a HER2 antibody of the presentinvention are joined with a flexible peptide linker (typically of about10, 12, 15 or more amino acid residues) in a single peptide chain.Methods of producing such antibodies are described in for instance U.S.Pat. No. 4,946,778, Pluckthun in The Pharmacology of MonoclonalAntibodies, vol. 113, Rosenburg and Moore eds. Springer-Verlag, NewYork, pp. 269-315 (1994), Bird et al., Science 242, 423-426 (1988),Huston et al., PNAS USA 85, 5879-5883 (1988) and McCafferty et al.,Nature 348, 552-554 (1990). The single chain antibody may be monovalent,if only a single VH and VL are used, bivalent, if two VH and VL areused, or polyvalent, if more than two VH and VL are used.

In one embodiment, the HER2 antibody of the invention is aneffector-function-deficient antibody. In one embodiment, theeffector-function-deficient HER2 antibody is a human stabilized IgG4antibody, which has been modified to prevent Fab-arm exchange (van derNeut Kolfschoten et al. (2007) Science 317(5844):1554-7). Examples ofsuitable human stabilized IgG4 antibodies are antibodies, whereinarginine at position 409 in a heavy chain constant region of human IgG4,which is indicated in the EU index as in Kabat et al., is substitutedwith lysine, threonine, methionine, or leucine, preferably lysine(described in WO2006033386 (Kirin)) and/or wherein the hinge region hasbeen modified to comprise a Cys-Pro-Pro-Cys sequence.

In one embodiment, the stabilized IgG4 HER2 antibody is an IgG4 antibodycomprising a heavy chain and a light chain, wherein said heavy chaincomprises a human IgG4 constant region having a residue selected fromthe group consisting of: Lys, Ala, Thr, Met and Leu at the positioncorresponding to 409 and/or a residue selected from the group consistingof: Ala, Val, Gly, Ile and Leu at the position corresponding to 405, andwherein said antibody optionally comprises one or more furthersubstitutions, deletions and/or insertions, but does not comprise aCys-Pro-Pro-Cys sequence in the hinge region. Preferably, said antibodycomprises a Lys or Ala residue at the position corresponding to 409 orthe CH3 region of the antibody has been replaced by the CH3 region ofhuman IgG1, of human IgG2 or of human IgG3. See also WO2008145142(Genmab).

In an even further embodiment, the stabilized IgG4 HER2 antibody is anIgG4 antibody comprising a heavy chain and a light chain, wherein saidheavy chain comprises a human IgG4 constant region having a residueselected from the group consisting of: Lys, Ala, Thr, Met and Leu at theposition corresponding to 409 and/or a residue selected from the groupconsisting of: Ala, Val, Gly, Ile and Leu at the position correspondingto 405, and wherein said antibody optionally comprises one or morefurther substitutions, deletions and/or insertions and wherein saidantibody comprises a Cys-Pro-Pro-Cys sequence in the hinge region.Preferably, said antibody comprises a Lys or Ala residue at the positioncorresponding to 409 or the CH3 region of the antibody has been replacedby the CH3 region of human IgG1, of human IgG2 or of human IgG3.

In a further embodiment, the effector-function-deficient HER2 antibodyis an antibody of a non-IgG4 type, e.g. IgG1, IgG2 or IgG3 which hasbeen mutated such that the ability to mediate effector functions, suchas ADCC, has been reduced or even eliminated. Such mutations have e.g.been described in Dall'Acqua W F et al., J Immunol. 177(2):1129-1138(2006) and Hezareh M, J Virol.; 75(24):12161-12168 (2001).

Conjugates

In a further embodiment, the present invention provides a HER2 antibodyor an HER2 bispecific antibody linked or conjugated to a therapeuticmoiety, such as a cytotoxin, a chemotherapeutic drug, a cytokine, animmunosuppressant, or a radioisotope. Such conjugates are referred toherein as “immunoconjugates”. Immunoconjugates which include one or morecytotoxins are referred to as “immunotoxins”.

A cytotoxin or cytotoxic agent includes any agent that is detrimental to(e.g., kills) cells. Suitable therapeutic agents for formingimmunoconjugates of the present invention include taxol, cytochalasin B,gramicidin D, ethidium bromide, emetine, mitomycin, etoposide,tenoposide, vincristine, vinblastine, colchicin, doxorubicin,daunorubicin, dihydroxy anthracin dione, maytansine or an analog orderivative thereof, mitoxantrone, mithramycin, actinomycin D,1-dehydrotestosterone, glucocorticoids, procaine, tetracaine, lidocaine,propranolol, and puromycin; calicheamicin or analogs or derivativesthereof; antimetabolites (such as methotrexate, 6-mercaptopurine,6-thioguanine, cytarabine, fludarabin, 5-fluorouracil, decarbazine,hydroxyurea, asparaginase, gemcitabine, cladribine), alkylating agents(such as mechlorethamine, thioepa, chlorambucil, melphalan, carmustine(BSNU), lomustine (CCNU), cyclophosphamide, busulfan, dibromomannitol,streptozotocin, dacarbazine (DTIC), procarbazine, mitomycin C, cisplatinand other platinum derivatives, such as carboplatin; as well asduocarmycin A, duocarmycin SA, CC-1065 (a.k.a. rachelmycin), or analogsor derivatives of CC-1065), antibiotics (such as dactinomycin (formerlyactinomycin), bleomycin, daunorubicin (formerly daunomycin),doxorubicin, idarubicin, mithramycin, mitomycin, mitoxantrone,plicamycin, anthramycin (AMC)), anti-mitotic agents (e.g.,tubulin-inhibitors) such as monomethyl auristatin E, monomethylauristatin F, or other analogs or derivatives of dolastatin 10;diphtheria toxin and related molecules (such as diphtheria A chain andactive fragments thereof and hybrid molecules); ricin toxin (such asricin A or a deglycosylated ricin A chain toxin), cholera toxin, aShiga-like toxin (SLT-I, SLT-II, SLT-IIV), LT toxin, C3 toxin, Shigatoxin, pertussis toxin, tetanus toxin, soybean Bowman-Birk proteaseinhibitor, Pseudomonas exotoxin, alorin, saporin, modeccin, gelanin,abrin A chain, modeccin A chain, alpha-sarcin, Aleurites fordiiproteins, dianthin proteins, Phytolacca americana proteins (PAPI, PAPII,and PAP-S), Momordica charantia inhibitor, curcin, crotin, Sapaonariaofficinalis inhibitor, gelonin, mitogellin, restrictocin, phenomycin,and enomycin toxins. Other suitable conjugated molecules includeantimicrobial/lytic peptides such as CLIP, Magainin 2, mellitin,Cecropin, and P18; ribonuclease (RNase), DNase I, Staphylococcalenterotoxin-A, pokeweed antiviral protein, diphtherin toxin, andPseudomonas endotoxin. See, for example, Pastan et al., Cell 47, 641(1986) and Goldenberg, Calif. A Cancer Journal for Clinicians 44, 43(1994). Therapeutic agents that may be administered in combination witha HER2 antibody of the present invention as described elsewhere herein,such as, e.g., anti-cancer cytokines or chemokines, are also candidatesfor therapeutic moieties useful for conjugation to an antibody of thepresent invention.

In one embodiment, a HER2 antibody of the invention comprises aconjugated nucleic acid or nucleic acid-associated molecule. In one suchembodiment, the conjugated nucleic acid is a cytotoxic ribonuclease, anantisense nucleic acid, an inhibitory RNA molecule (e.g., a siRNAmolecule) or an immunostimulatory nucleic acid (e.g., animmunostimulatory CpG motif-containing DNA molecule). In anotherembodiment, a HER2 antibody of the invention is conjugated to an aptameror a ribozyme.

In one embodiment, HER2 antibodies comprising one or more radiolabeledamino acids are provided. A radiolabeled HER2 antibody may be used forboth diagnostic and therapeutic purposes (conjugation to radiolabeledmolecules is another possible feature). Non-limiting examples of labelsfor polypeptides include 3H, 14C, 15N, 35S, 90Y, 99Tc, and 125I, 131I,and 186Re.

In one embodiment, the antibody is conjugated to a radioisotope or to aradioisotope-containing chelate. For example, the antibody can beconjugated to a chelator linker, e.g. DOTA, DTPA or tiuxetan, whichallows for the antibody to be complexed with a radioisotope. Theantibody may also or alternatively comprise or be conjugated to one ormore radiolabeled amino acids or other radiolabeled molecule. Aradiolabeled CD74 Ab may be used for both diagnostic and therapeuticpurposes. Non-limiting examples of radioisotopes include ³H, ¹⁴C, ¹⁵N,³⁵S, ⁹⁰Y, ⁹⁹Tc, ¹²⁵I, ¹¹¹In, ¹³¹In, ¹⁸⁶Re, ²¹³Bs, ²²⁵Ac and ²²⁷Th.

HER2 antibodies may also be chemically modified by covalent conjugationto a polymer to for instance increase their circulating half-life.Exemplary polymers, and methods to attach them to peptides, areillustrated in for instance U.S. Pat. Nos. 4,766,106, 4,179,337,4,495,285 and 4,609,546. Additional polymers include polyoxyethylatedpolyols and polyethylene glycol (PEG) (e.g., a PEG with a molecularweight of between about 1,000 and about 40,000, such as between about2,000 and about 20,000).

Any method known in the art for conjugating the HER2 antibody to theconjugated molecule(s), such as those described above, may be employed,including the methods described by Hunter et al., Nature 144, 945(1962), David et al., Biochemistry 13, 1014 (1974), Pain et al., J.Immunol. Meth. 40, 219 (1981) and Nygren, J. Histochem. and Cytochem. 3,407 (1982). Such antibodies may be produced by chemically conjugatingthe other moiety to the N-terminal side or C-terminal side of the HER2antibody or fragment thereof (e.g., a HER2 antibody H or L chain) (see,e.g., Antibody Engineering Handbook, edited by Osamu Kanemitsu,published by Chijin Shokan (1994)). Such conjugated antibody derivativesmay also be generated by conjugation at internal residues or sugars,where appropriate.

The agents may be coupled either directly or indirectly to a HER2antibody of the present invention. One example of indirect coupling of asecond agent is coupling via a spacer moiety to cysteine or lysineresidues in the antibody. In one embodiment, a HER2 antibody isconjugated to a prodrug molecule that can be activated in vivo to atherapeutic drug via a spacer or linker. After administration, thespacers or linkers are cleaved by tumor-cell associated enzymes or othertumor-specific conditions, by which the active drug is formed. Examplesof such prodrug technologies and linkers are described in WO02083180,WO2004043493, WO2007018431, WO2007089149, and WO2009017394 by Syntarga BV, et al. Suitable antibody-prodrug technology and duocarmycin analogscan also be found in U.S. Pat. No. 6,989,452 (Medarex).

In one embodiment, the HER2 antibody of the present invention isattached to a chelator linker, e.g. tiuxetan, which allows for theantibody to be conjugated to a radioisotope.

Bispecific Antibodies

In a further aspect, the invention relates to a bispecific moleculecomprising a first antigen binding site from a HER2 antibody of theinvention as described herein above and a second antigen binding sitewith a different binding specificity, such as a binding specificity fora human effector cell, a human Fc receptor, a T cell receptor, a B cellreceptor or a binding specificity for a non-overlapping epitope of HER2,i.e. a bispecific antibody wherein the first and second antigen bindingsites do not cross-block each other for binding to HER2, e.g. whentested as described in Example 14.

Exemplary bispecific antibody molecules of the invention comprise (i)two antibodies, one with a specificity to HER2 and another to a secondtarget that are conjugated together, (ii) a single antibody that has onechain or arm specific to HER2 and a second chain or arm specific to asecond molecule, (iii) a single chain antibody that has specificity toHER2 and a second molecule, e.g., via two scFvs linked in tandem by anextra peptide linker; (iv) a dual-variable-domain antibody (DVD-Ig),where each light chain and heavy chain contains two variable domains intandem through a short peptide linkage (Wu et al., Generation andCharacterization of a Dual Variable Domain Immunoglobulin (DVD-Ig™)Molecule, In: Antibody Engineering, Springer Berlin Heidelberg (2010));(v) a chemically-linked bispecific (Fab′)₂ fragment; (vi) a Tandab,which is a fusion of two single chain diabodies resulting in atetravalent bispecific antibody that has two binding sites for each ofthe target antigens; (vii) a flexibody, which is a combination of scFvswith a diabody resulting in a multivalent molecule; (viii) a so called“dock and lock” molecule, based on the “dimerization and docking domain”in Protein Kinase A, which, when applied to Fabs, can yield a trivalentbispecific binding protein consisting of two identical Fab fragmentslinked to a different Fab fragment; (ix) a so-called Scorpion molecule,comprising, e.g., two scFvs fused to both termini of a human Fc-region;and (x) a diabody. In one embodiment, the bispecific antibody of thepresent invention is a diabody, a cross-body, or a bispecific obtainedvia a controlled Fab arm exchange as those described in the presentinvention.

Examples of platforms useful for preparing bispecific antibodies includebut are not limited to BiTE (Micromet), DART (MacroGenics), Fcab andMab² (F-star), Fc-engineered IgG1 (Xencor) or DuoBody (based on Fab armexchange, Genmab, this application).

Examples of different classes of bispecific antibodies include but arenot limited to

-   -   asymmetric IgG-like molecules, wherein the one side of the        molecule contains the Fab region or part of the Fab region of at        least one antibody, and the other side of the molecule contains        the Fab region or parts of the Fab region of at least one other        antibody; in this class, asymmetry in the Fc region could also        be present, and be used for specific linkage of the two parts of        the molecule;    -   symmetric IgG-like molecules, wherein the two sides of the        molecule each contain the Fab region or part of the Fab region        of at least two different antibodies;    -   IgG fusion molecules, wherein full length IgG antibodies are        fused to extra Fab regions or parts of Fab regions;    -   Fc fusion molecules, wherein single chain Fv molecules or        stabilized diabodies are fused to Fcγ regions or parts thereof;    -   Fab fusion molecules, wherein different Fab-fragments are fused        together;    -   ScFv- and diabody-based molecules wherein different single chain        Fv molecules or different diabodies are fused to each other or        to another protein or carrier molecule.

Examples of asymmetric IgG-like molecules include but are not limited tothe Triomab/Quadroma (Trion Pharma/Fresenius Biotech), theKnobs-into-Holes (Genentech), CrossMAbs (Roche) and theelectrostatically-matched (Amgen), the LUZ-Y (Genentech), the StrandExchange Engineered Domain body (EMD Serono), the Biclonic (Merus) andthe DuoBody (Genmab A/S).

Example of symmetric IgG-like molecules include but are not limited toDual Targeting (DT)-Ig (GSK/Domantis), Two-in-one Antibody (Genentech),Cross-linked Mabs (Karmanos Cancer Center), mAb² (F-Star) and CovX-body(CovX/Pfizer).

Examples of IgG fusion molecules include but are not limited to DualVariable Domain (DVD)-Ig (Abbott), IgG-like Bispecific (ImClone/EliLilly), Ts2Ab (MedImmune/AZ) and BsAb (Zymogenetics), HERCULES (BiogenIdec) and TvAb (Roche).

Examples of Fc fusion molecules include but are not limited to ScFv/FcFusions (Academic Institution), SCORPION (Emergent BioSolutions/Trubion,Zymogenetics/BMS), Dual Affinity Retargeting Technology (Fc-DART)(MacroGenics) and Dual(ScFv)₂-Fab (National Research Center for AntibodyMedicine—China).

Examples of class V bispecific antibodies include but are not limited toF(ab)₂ (Medarex/AMGEN), Dual-Action or Bis-Fab (Genentech),Dock-and-Lock (DNL) (ImmunoMedics), Bivalent Bispecific (Biotecnol) andFab-Fv (UCB-Celltech).

Examples of ScFv- and diabody-based molecules include but are notlimited to Bispecific T Cell Engager (BiTE) (Micromet9, Tandem Diabody(Tandab) (Affimed), Dual Affinity Retargeting Technology (DART)(MacroGenics), Single-chain Diabody (Academic), TCR-like Antibodies(AIT, ReceptorLogics), Human Serum Albumin ScFv Fusion (Merrimack) andCOMBODY (Epigen Biotech).

In one embodiment, the second molecule is a cancerantigen/tumor-associated antigen such as carcinoembryonic antigen (CEA),prostate specific antigen (PSA), RAGE (renal antigen), α-fetoprotein,CAMEL (CTL-recognized antigen on melanoma), CT antigens (such asMAGE-B5, -B6, -C2, -C3, and D; Mage-12; CT10; NY-ESO-1, SSX-2, GAGE,BAGE, MAGE, and SAGE), mucin antigens (e.g., MUC1, mucin-CA125, etc.),ganglioside antigens, tyrosinase, gp75, c-Met, C-myc, Marti, MelanA,MUM-1, MUM-2, MUM-3, HLA-B7, Ep-CAM or a cancer-associated integrin,such as a503 integrin. In another embodiment, the second molecule is a Tcell and/or NK cell antigen, such as CD3 or CD16. In another embodiment,the second molecule is an angiogenic factor or other cancer-associatedgrowth factor, such as a vascular endothelial growth factor, afibroblast growth factor, epidermal growth factor, angiogenin or areceptor of any of these, particularly receptors associated with cancerprogression (for instance another one of the HER receptors; HER1, HER3,or HER4). In one embodiment, the second antigen-binding site binds adifferent, preferably non-blocking, site on HER2 than the one bound bythe antibody of the invention. For example, the second molecule may bederived from, or cross-block HER2-binding of, trastuzumab, pertuzumab,F5, or C1.

Methods of preparing bispecific antibodies include those described in WO2008119353 (Genmab) and reported van der Neut-Kolfschoten et al.(Science. 2007 Sep. 14; 317(5844):1554-7) and it may for example beperformed as described in example 20 of the present invention.

Nucleic Acid Sequences, Vectors and Host Cells

In a further aspect, the invention relates to nucleic acid sequences,such as DNA sequences, encoding heavy and light chains of an antibody ofthe invention.

In one embodiment, the nucleic acid sequence encodes an amino acidsequence selected from the group consisting of: SEQ ID NO: 1, 5, 8, 12,15, 19, 22, 26, 29, 32, 35, 39, 42, 46, 49, 53, 56, 60, 63, 67, 70, 74,77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94,95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109,110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123,124, 125 and 126.

In another particular embodiment, the nucleic acid sequence encodes a VHamino acid sequence selected from the group consisting of: SEQ ID NO: 1,8, 15, 22, 29, 35, 42, 49, 56, 63, 70, 77, 79, 81, 83, 85, 87, 89, 91,93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121,123, and 125.

In another particular embodiment, the nucleic acid sequence encodes a VLamino acid sequence selected from the group consisting of: SEQ ID NO: 5,12, 19, 26, 32, 39, 46, 53, 60, 67, 74, 78, 80, 82, 84, 86, 88, 90, 92,94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122,124, and 126.

In an even further aspect, the invention relates to an expressionvector, or a set of expression vectors, encoding an antibody of theinvention. The heavy and light chain of the antibody may be encoded bythe same vector or by different vector.

Such expression vectors may be used for recombinant production ofantibodies of the invention.

In one embodiment, the expression vector of the invention comprises anucleotide sequence encoding one or more of the amino acid sequencesselected from the group consisting of: SEQ ID NO: 1, 5, 8, 12, 15, 19,22, 26, 29, 32, 35, 39, 42, 46, 49, 53, 56, 60, 63, 67, 70, 74, 77, 78,79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96,97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111,112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125 and126.

In another particular embodiment, the expression vector of the inventioncomprises a nucleotide sequence encoding one or more of the VH aminoacid sequences selected from the group consisting of: SEQ ID NO: 1, 8,15, 22, 29, 35, 42, 49, 56, 63, 70, 77, 79, 81, 83, 85, 87, 89, 91, 93,95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 117, 119, 121, 123,and 125.

In another particular embodiment, the expression vector of the inventioncomprises a nucleotide sequence encoding one or more of the VL aminoacid sequences selected from the group consisting of: SEQ ID NO: 5, 12,19, 26, 32, 39, 46, 53, 60, 67, 74, 78, 80, 82, 84, 86, 88, 90, 92, 94,96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124,and 126.

In a further embodiment, the expression vector further comprises anucleotide sequence encoding the constant region of a light chain, aheavy chain or both light and heavy chains of an antibody, e.g. a humanantibody.

An expression vector in the context of the present invention may be anysuitable vector, including chromosomal, non-chromosomal, and syntheticnucleic acid vectors (a nucleic acid sequence comprising a suitable setof expression control elements). Examples of such vectors includederivatives of SV40, bacterial plasmids, phage DNA, baculovirus, yeastplasmids, vectors derived from combinations of plasmids and phage DNA,and viral nucleic acid (RNA or DNA) vectors. In one embodiment, a HER2antibody-encoding nucleic acid is comprised in a naked DNA or RNAvector, including, for example, a linear expression element (asdescribed in for instance Sykes and Johnston, Nat Biotech 17, 355-59(1997)), a compacted nucleic acid vector (as described in for instanceU.S. Pat. No. 6,077,835 and/or WO 00/70087), a plasmid vector such aspBR322, pUC 19/18, or pUC 118/119, a “midge” minimally-sized nucleicacid vector (as described in for instance Schakowski et al., Mol Ther 3,793-800 (2001)), or as a precipitated nucleic acid vector construct,such as a CaPO4-precipitated construct (as described in for instance WO00/46147, Benvenisty and Reshef, PNAS USA 83, 9551-55 (1986), Wigler etal., Cell 14, 725 (1978), and Coraro and Pearson, Somatic Cell Genetics7, 603 (1981)). Such nucleic acid vectors and the usage thereof are wellknown in the art (see for instance U.S. Pat. Nos. 5,589,466 and5,973,972).

Exemplary expression vectors for the antibodies of the invention arealso described in Examples 2 and 3.

In one embodiment, the vector is suitable for expression of the HER2antibody in a bacterial cell. Examples of such vectors includeexpression vectors such as BlueScript (Stratagene), pIN vectors (VanHeeke & Schuster, J Biol Chem 264, 5503-5509 (1989), pET vectors(Novagen, Madison Wis.) and the like).

An expression vector may also or alternatively be a vector suitable forexpression in a yeast system. Any vector suitable for expression in ayeast system may be employed. Suitable vectors include, for example,vectors comprising constitutive or inducible promoters such as alphafactor, alcohol oxidase and PGH (reviewed in: F. Ausubel et al., ed.Current Protocols in Molecular Biology, Greene Publishing and WileyInterScience New York (1987), and Grant et al., Methods in Enzymol 153,516-544 (1987)).

An expression vector may also or alternatively be a vector suitable forexpression in mammalian cells, e.g. a vector comprising glutaminesynthetase as a selectable marker, such as the vectors described inBebbington (1992) Biotechnology (NY) 10:169-175.

A nucleic acid and/or vector may also comprises a nucleic acid sequenceencoding a secretion/localization sequence, which can target apolypeptide, such as a nascent polypeptide chain, to the periplasmicspace or into cell culture media. Such sequences are known in the art,and include secretion leader or signal peptides.

In an expression vector of the invention, HER2 antibody-encoding nucleicacids may comprise or be associated with any suitable promoter,enhancer, and other expression-facilitating elements. Examples of suchelements include strong expression promoters (e. g., human CMV IEpromoter/enhancer as well as RSV, SV40, SL3-3, MMTV, and HIV LTRpromoters), effective poly (A) termination sequences, an origin ofreplication for plasmid product in E. coli, an antibiotic resistancegene as selectable marker, and/or a convenient cloning site (e.g., apolylinker). Nucleic acids may also comprise an inducible promoter asopposed to a constitutive promoter such as CMV IE.

In one embodiment, the HER2 antibody-encoding expression vector may bepositioned in and/or delivered to the host cell or host animal via aviral vector.

In an even further aspect, the invention relates to a recombinanteukaryotic or prokaryotic host cell, such as a transfectoma, whichproduces an antibody of the invention as defined herein. Examples ofhost cells include yeast, bacterial, and mammalian cells, such as CHO orHEK cells. For example, in one embodiment, the present inventionprovides a cell comprising a nucleic acid stably integrated into thecellular genome that comprises a sequence coding for expression of aHER2 antibody of the present invention. In another embodiment, thepresent invention provides a cell comprising a non-integrated nucleicacid, such as a plasmid, cosmid, phagemid, or linear expression element,which comprises a sequence coding for expression of a HER2 antibody ofthe invention.

In a further aspect, the invention relates to a hybridoma which producesan antibody of the invention as defined herein. In an even furtheraspect, the invention relates to a transgenic non-human animal or plantcomprising nucleic acids encoding a human heavy chain and a human lightchain, wherein the animal or plant produces an antibody of the inventionof the invention.

In a further aspect, the invention relates to a method for producing aHER2 antibody of the invention, said method comprising the steps of

-   a) culturing a hybridoma or a host cell of the invention as    described herein above, and-   b) purifying the antibody of the invention from the culture media.

Compositions

In a further main aspect, the invention relates to a pharmaceuticalcomposition comprising:

-   -   a HER2 antibody as defined herein, and    -   a pharmaceutically-acceptable carrier.

The pharmaceutical composition of the present invention may contain oneantibody of the present invention or a combination of differentantibodies of the present invention.

The pharmaceutical compositions may be formulated in accordance withconventional techniques such as those disclosed in Remington: TheScience and Practice of Pharmacy, 19th Edition, Gennaro, Ed., MackPublishing Co., Easton, Pa., 1995. A pharmaceutical composition of thepresent invention may e.g. include diluents, fillers, salts, buffers,detergents (e. g., a nonionic detergent, such as Tween-20 or Tween-80),stabilizers (e. g., sugars or protein-free amino acids), preservatives,tissue fixatives, solubilizers, and/or other materials suitable forinclusion in a pharmaceutical composition.

Pharmaceutically acceptable carriers include any and all suitablesolvents, dispersion media, coatings, antibacterial and antifungalagents, isotonicity agents, antioxidants and absorption delaying agents,and the like that are physiologically compatible with a compound of thepresent invention. Examples of suitable aqueous and nonaqueous carrierswhich may be employed in the pharmaceutical compositions of the presentinvention include water, saline, phosphate buffered saline, ethanol,dextrose, polyols (such as glycerol, propylene glycol, polyethyleneglycol, and the like), and suitable mixtures thereof, vegetable oils,carboxymethyl cellulose colloidal solutions, tragacanth gum andinjectable organic esters, such as ethyl oleate, and/or various buffers.Pharmaceutically acceptable carriers include sterile aqueous solutionsor dispersions and sterile powders for the extemporaneous preparation ofsterile injectable solutions or dispersion. Proper fluidity may bemaintained, for example, by the use of coating materials, such aslecithin, by the maintenance of the required particle size in the caseof dispersions, and by the use of surfactants.

Pharmaceutical compositions of the present invention may also comprisepharmaceutically acceptable antioxidants for instance (1) water solubleantioxidants, such as ascorbic acid, cysteine hydrochloride, sodiumbisulfate, sodium metabisulfite, sodium sulfite and the like; (2)oil-soluble antioxidants, such as ascorbyl palmitate, butylatedhydroxyanisole, butylated hydroxytoluene, lecithin, propyl gallate,alpha-tocopherol, and the like; and (3) metal chelating agents, such ascitric acid, ethylenediamine tetraacetic acid (EDTA), sorbitol, tartaricacid, phosphoric acid, and the like.

Pharmaceutical compositions of the present invention may also compriseisotonicity agents, such as sugars, polyalcohols, such as mannitol,sorbitol, glycerol or sodium chloride in the compositions.

The pharmaceutical compositions of the present invention may alsocontain one or more adjuvants appropriate for the chosen route ofadministration such as preservatives, wetting agents, emulsifyingagents, dispersing agents, preservatives or buffers, which may enhancethe shelf life or effectiveness of the pharmaceutical composition. Thecompounds of the present invention may be prepared with carriers thatwill protect the compound against rapid release, such as a controlledrelease formulation, including implants, transdermal patches, andmicroencapsulated delivery systems. Such carriers may include gelatin,glyceryl monostearate, glyceryl distearate, biodegradable, biocompatiblepolymers such as ethylene vinyl acetate, polyanhydrides, polyglycolicacid, collagen, polyorthoesters, and polylactic acid alone or with awax, or other materials well known in the art. Methods for thepreparation of such formulations are generally known to those skilled inthe art.

Sterile injectable solutions may be prepared by incorporating the activecompound in the required amount in an appropriate solvent with one or acombination of ingredients e.g. as enumerated above, as required,followed by sterilization microfiltration. Generally, dispersions areprepared by incorporating the active compound into a sterile vehiclethat contains a basic dispersion medium and the required otheringredients e.g. from those enumerated above. In the case of sterilepowders for the preparation of sterile injectable solutions, examples ofmethods of preparation are vacuum drying and freeze-drying(lyophilization) that yield a powder of the active ingredient plus anyadditional desired ingredient from a previously sterile-filteredsolution thereof.

The actual dosage levels of the active ingredients in the pharmaceuticalcompositions may be varied so as to obtain an amount of the activeingredient which is effective to achieve the desired therapeuticresponse for a particular patient, composition, and mode ofadministration, without being toxic to the patient. The selected dosagelevel will depend upon a variety of pharmacokinetic factors includingthe activity of the particular compositions of the present inventionemployed, or the amide thereof, the route of administration, the time ofadministration, the rate of excretion of the particular compound beingemployed, the duration of the treatment, other drugs, compounds and/ormaterials used in combination with the particular compositions employed,the age, sex, weight, condition, general health and prior medicalhistory of the patient being treated, and like factors well known in themedical arts.

The pharmaceutical composition may be administered by any suitable routeand mode. In one embodiment, a pharmaceutical composition of the presentinvention is administered parenterally. “Administered parenterally” asused herein means modes of administration other than enteral and topicaladministration, usually by injection, and include epidermal,intravenous, intramuscular, intraarterial, intrathecal, intracapsular,intraorbital, intracardiac, intradermal, intraperitoneal,intratendinous, transtracheal, subcutaneous, subcuticular,intraarticular, subcapsular, subarachnoid, intraspinal, intracranial,intrathoracic, epidural and intrasternal injection and infusion.

In one embodiment that pharmaceutical composition is administered byintravenous or subcutaneous injection or infusion.

Uses

In a further main aspect, the invention relates to a HER2 antibody ofthe invention for use as a medicament.

The HER2 antibodies of the invention may be used for a number ofpurposes. In particular, the antibodies of the invention may be used forthe treatment of various forms of cancer, including metastatic cancerand refractory cancer.

In one embodiment, the HER2 antibodies of the invention are used for thetreatment of breast cancer, including primary, metastatic, andrefractory breast cancer.

In one embodiment, the HER2 antibodies of the invention are used for thetreatment of a form of cancer selected from the group consisting ofprostate cancer, non-small cell lung cancer, bladder cancer, ovariancancer, gastric cancer, colorectal cancer, esophageal cancer, squamouscell carcinoma of the head & neck, cervical cancer, pancreatic cancer,testis cancer, malignant melanoma and a soft-tissue cancer (e.g.synovial sarcoma).

Similarly, the invention relates to a method for killing a tumor cellexpressing HER2, comprising administration, to an individual in needthereof, of an effective amount of an antibody of the invention, such asan antibody drug-conjugate (ADC).

In one embodiment, said tumor cell is involved in a form of cancerselected from the group consisting of: breast cancer, prostate cancer,non-small cell lung cancer, bladder cancer, ovarian cancer, gastriccancer, colorectal cancer, esophageal cancer and squamous cell carcinomaof the head & neck, cervical cancer, pancreatic cancer, testis cancer,malignant melanoma, and a soft-tissue cancer (e.g., synovial sarcoma).

In one embodiment, the tumor cell is one that co-expresses HER2 and atleast one other member of the EGFR family, preferably EGFR, HER3, orboth of EGFR and HER3, and is a tumor cell involved in breast cancer,colorectal cancer, endometrial/cervical cancer, lung cancer, malignantmelanoma, ovarian cancer, pancreatic cancer, prostate cancer, testiscancer, a soft-tissue tumor (e.g., synovial sarcoma), or bladder cancer.

In one aspect, the invention relates to a method for treating cancer ina subject, comprising selecting a subject suffering from a cancercomprising tumor cells co-expressing HER2 and EGFR and/or HER3, andadministering to the subject an antibody of the invention, optionally inthe form of an antibody conjugated to a cytotoxic agent or drug. In oneembodiment, the subject suffers from a cancer selected from the groupconsisting of breast cancer, colorectal cancer, endometrial/cervicalcancer, lung cancer, malignant melanoma, ovarian cancer, pancreaticcancer, prostate cancer, testis cancer, a soft-tissue tumor (e.g.,synovial sarcoma), or bladder cancer.

Also, the invention relates to the use of a monoclonal antibody thatbinds to human HER2 for the preparation of a medicament for thetreatment of cancer, such as one of the specific cancer indicationsmentioned above.

The invention further relates to a monoclonal antibody for use in thetreatment of cancer, such as one of the cancer indications mentionedabove.

In a further embodiment of the methods of treatment of the presentinvention, the efficacy of the treatment is being monitored during thetherapy, e.g. at predefined points in time, by determining tumor burdenor HER2 expression levels on the relevant tumor cells.

Dosage regimens in the above methods of treatment and uses are adjustedto provide the optimum desired response (e.g., a therapeutic response).For example, a single bolus may be administered, several divided dosesmay be administered over time or the dose may be proportionally reducedor increased as indicated by the exigencies of the therapeuticsituation. Parenteral compositions may be formulated in dosage unit formfor ease of administration and uniformity of dosage.

The efficient dosages and the dosage regimens for the HER2 antibodiesdepend on the disease or condition to be treated and may be determinedby the persons skilled in the art. An exemplary, non-limiting range fora therapeutically effective amount of a compound of the presentinvention is about 0.1-100 mg/kg, such as about 0.1-50 mg/kg, forexample about 0.1-20 mg/kg, such as about 0.1-10 mg/kg, for instanceabout 0.5, about such as 0.3, about 1, about 3, about 5, or about 8mg/kg.

A physician or veterinarian having ordinary skill in the art may readilydetermine and prescribe the effective amount of the pharmaceuticalcomposition required. For example, the physician or veterinarian couldstart doses of the HER2 antibody employed in the pharmaceuticalcomposition at levels lower than that required in order to achieve thedesired therapeutic effect and gradually increase the dosage until thedesired effect is achieved. In general, a suitable daily dose of acomposition of the present invention will be that amount of the compoundwhich is the lowest dose effective to produce a therapeutic effect.Administration may e.g. be parenteral, such as intravenous,intramuscular or subcutaneous. In one embodiment, the HER2 antibodiesmay be administered by infusion in a weekly dosage of from 10 to 500mg/m², such as of from 200 to 400 mg/m². Such administration may berepeated, e.g., 1 to 8 times, such as 3 to 5 times. The administrationmay be performed by continuous infusion over a period of from 2 to 24hours, such as of from 2 to 12 hours. In one embodiment, the HER2antibodies may be administered by slow continuous infusion over a longperiod, such as more than 24 hours, in order to reduce toxic sideeffects.

In one embodiment the HER2 antibodies may be administered in a weeklydosage of from 250 mg to 2000 mg, such as for example 300 mg, 500 mg,700 mg, 1000 mg, 1500 mg or 2000 mg, for up to 8 times, such as from 4to 6 times when given once a week. Such regimen may be repeated one ormore times as necessary, for example, after 6 months or 12 months. Thedosage may be determined or adjusted by measuring the amount of compoundof the present invention in the blood upon administration by forinstance taking out a biological sample and using anti-idiotypicantibodies which target the antigen binding region of the HER2antibodies of the present invention.

The efficient dosages and the dosage regimens for the bispecificantibodies depend on the disease or condition to be treated and may bedetermined by the persons skilled in the art. An exemplary, non-limitingrange for a therapeutically effective amount of a bispecific antibody ofthe present invention is about 0.1-100 mg/kg, such as about 0.1-50mg/kg, for example about 0.1-20 mg/kg, such as about 0.1-10 mg/kg, forinstance about 0.5, about such as 0.3, about 1, about 3, about 5, orabout 8 mg/kg.

In one embodiment, the HER2 antibodies may be administered bymaintenance therapy, such as, e.g., once a week for a period of 6 monthsor more.

A HER2 antibody may also be administered prophylactically in order toreduce the risk of developing cancer, delay the onset of the occurrenceof an event in cancer progression, and/or reduce the risk of recurrencewhen a cancer is in remission.

HER2 antibodies may also be administered in combination therapy, i.e.,combined with other therapeutic agents relevant for the disease orcondition to be treated. Accordingly, in one embodiment, theantibody-containing medicament is for combination with one or morefurther therapeutic agent, such as a cytotoxic, chemotherapeutic oranti-angiogenic agent.

Such combined administration may be simultaneous, separate orsequential. For simultaneous administration the agents may beadministered as one composition or as separate compositions, asappropriate. The present invention thus also provides methods fortreating a disorder involving cells expressing HER2 as described above,which methods comprise administration of a HER2 antibody of the presentinvention combined with one or more additional therapeutic agents asdescribed below.

In one embodiment, the present invention provides a method for treatinga disorder involving cells expressing HER2 in a subject, which methodcomprises administration of a therapeutically effective amount of a HER2antibody of the present invention, and optionally at least oneadditional therapeutic agent, or an antibody binding to a differentepitope than said HER2 antibody, to a subject in need thereof.

In one embodiment, the present invention provides a method for treatingor preventing cancer, which method comprises administration of atherapeutically effective amount of a HER2 antibody of the presentinvention and at least one additional therapeutic agent to a subject inneed thereof.

In one embodiment, such an additional therapeutic agent may be selectedfrom an antimetabolite, such as methotrexate, 6-mercaptopurine,6-thioguanine, cytarabine, fludarabine, 5-fluorouracil, decarbazine,hydroxyurea, asparaginase, gemcitabine or cladribine.

In another embodiment, such an additional therapeutic agent may beselected from an alkylating agent, such as mechlorethamine, thioepa,chlorambucil, melphalan, carmustine (BSNU), lomustine (CCNU),cyclophosphamide, busulfan, dibromomannitol, streptozotocin, dacarbazine(DTIC), procarbazine, mitomycin C, cisplatin and other platinumderivatives, such as carboplatin.

In another embodiment, such an additional therapeutic agent may beselected from an anti-mitotic agent, such as taxanes, for instancedocetaxel, and paclitaxel, and vinca alkaloids, for instance vindesine,vincristine, vinblastine, and vinorelbine.

In another embodiment, such an additional therapeutic agent may beselected from a topoisomerase inhibitor, such as topotecan oririnotecan, or a cytostatic drug, such as etoposide and teniposide.

In another embodiment, such an additional therapeutic agent may beselected from a growth factor inhibitor, such as an inhibitor of ErbB1(EGFR) (such as an EGFR antibody, e.g. zalutumumab, cetuximab,panitumumab or nimotuzumab or other EGFR inhibitors, such as gefitinibor erlotinib), another inhibitor of ErbB2 (HER2/neu) (such as a HER2antibody, e.g. trastuzumab, trastuzumab-DM1 or pertuzumab) or aninhibitor of both EGFR and HER2, such as lapatinib).

In another embodiment, such an additional therapeutic agent may beselected from a tyrosine kinase inhibitor, such as imatinib (Glivec,Gleevec STI571) or lapatinib, PTK787/ZK222584.

In another embodiment, the present invention provides a method fortreating a disorder involving cells expressing HER2 in a subject, whichmethod comprises administration of a therapeutically effective amount ofan HER2 antibody of the present invention and at least one inhibitor ofangiogenesis, neovascularization, and/or other vascularization to asubject in need thereof

Examples of such angiogenesis inhibitors are urokinase inhibitors,matrix metalloprotease inhibitors (such as marimastat, neovastat, BAY12-9566, AG 3340, BMS-275291 and similar agents), inhibitors ofendothelial cell migration and proliferation (such as TNP-470,squalamine, 2-methoxyestradiol, combretastatins, endostatin,angiostatin, penicillamine, SCH66336 (Schering-Plough Corp, Madison,N.J.), R115777 (Janssen Pharmaceutica, Inc, Titusville, N.J.) andsimilar agents), antagonists of angiogenic growth factors (such as suchas ZD6474, SU6668, antibodies against angiogenic agents and/or theirreceptors (such as VEGF (e.g. bevacizumab), bFGF, and angiopoietin-1),thalidomide, thalidomide analogs (such as CC-5013), Sugen 5416, SU5402,antiangiogenic ribozyme (such as angiozyme), interferon α (such asinterferon α2a), suramin and similar agents), VEGF-R kinase inhibitorsand other anti-angiogenic tyrosine kinase inhibitors (such as SU011248),inhibitors of endothelial-specific integrin/survival signaling (such asvitaxin and similar agents), copper antagonists/chelators (such astetrathiomolybdate, captopril and similar agents), carboxyamido-triazole(CAI), ABT-627, CM101, interleukin-12 (IL-12), IM862, PNU145156E as wellas nucleotide molecules inhibiting angiogenesis (such asantisense-VEGF-cDNA, cDNA coding for angiostatin, cDNA coding for p53and cDNA coding for deficient VEGF receptor-2).

Other examples of such inhibitors of angiogenesis, neovascularization,and/or other vascularization are anti-angiogenic heparin derivatives(e.g., heperinase III), temozolomide, NK4, macrophage migrationinhibitory factor, cyclooxygenase-2 inhibitors, inhibitors ofhypoxia-inducible factor 1, anti-angiogenic soy isoflavones, oltipraz,fumagillin and analogs thereof, somatostatin analogues, pentosanpolysulfate, tecogalan sodium, dalteparin, tumstatin, thrombospondin,NM-3, combrestatin, canstatin, avastatin, antibodies against othertargets, such as anti-alpha-v/beta-3 integrin and anti-kininostatinantibodies.

In one embodiment, a therapeutic agent for use in combination with aHER2 antibody for treating the disorders as described above may be ananti-cancer immunogen, such as a cancer antigen/tumor-associated antigen(e.g., epithelial cell adhesion molecule (EpCAM/TACSTD1), mucin 1(MUC1), carcinoembryonic antigen (CEA), tumor-associated glycoprotein 72(TAG-72), gp100, Melan-A, MART-1, KDR, RCAS1, MDA7, cancer-associatedviral vaccines (e.g., human papillomavirus vaccines) or tumor-derivedheat shock proteins,

In one embodiment, a therapeutic agent for use in combination with aHER2 antibody for treating the disorders as described above may be ananti-cancer cytokine, chemokine, or combination thereof. Examples ofsuitable cytokines and growth factors include IFNγ, IL-2, IL-4, IL-6,IL-7, IL-10, IL-12, IL-13, IL-15, IL-18, IL-23, IL-24, IL-27, IL-28a,IL-28b, IL-29, KGF, IFNα (e.g., INFα2b), IFNβ, GM-CSF, CD40L, Flt3ligand, stem cell factor, ancestim, and TNFα. Suitable chemokines mayinclude Glu-Leu-Arg (ELR)-negative chemokines such as IP-10, MCP-3, MIG,and SDF-1α from the human CXC and C—C chemokine families. Suitablecytokines include cytokine derivatives, cytokine variants, cytokinefragments, and cytokine fusion proteins.

In one embodiment, a therapeutic agent for use in combination with aHER2 antibody for treating the disorders as described above may be acell cycle control/apoptosis regulator (or “regulating agent”). A cellcycle control/apoptosis regulator may include molecules that target andmodulate cell cycle control/apoptosis regulators such as (i) cdc-25(such as NSC 663284), (ii) cyclin-dependent kinases that overstimulatethe cell cycle (such as flavopiridol (L868275, HMR1275),7-hydroxystaurosporine (UCN-01, KW-2401), and roscovitine(R-roscovitine, CYC202)), and (iii) telomerase modulators (such asBIBR1532, SOT-095, GRN163 and compositions described in for instanceU.S. Pat. Nos. 6,440,735 and 6,713,055). Non-limiting examples ofmolecules that interfere with apoptotic pathways include TNF-relatedapoptosis-inducing ligand (TRAIL)/apoptosis-2 ligand (Apo-2L),antibodies that activate TRAIL receptors, IFNs,□ and anti-sense Bcl-2.

In one embodiment, a therapeutic agent for use in combination with aHER2 antibody for treating the disorders as described above may be ahormonal regulating agent, such as agents useful for anti-androgen andanti-estrogen therapy. Examples of such hormonal regulating agents aretamoxifen, idoxifene, fulvestrant, droloxifene, toremifene, raloxifene,diethylstilbestrol, ethinyl estradiol/estinyl, an antiandrogene (such asflutaminde/eulexin), a progestin (such as such as hydroxyprogesteronecaproate, medroxy-progesterone/provera, megestrol acepate/megace), anadrenocorticosteroid (such as hydrocortisone, prednisone), luteinizinghormone-releasing hormone (and analogs thereof and other LHRH agonistssuch as buserelin and goserelin), an aromatase inhibitor (such asanastrazole/arimidex, aminoglutethimide/cytraden, exemestane) or ahormone inhibitor (such as octreotide/sandostatin).

In one embodiment, a therapeutic agent for use in combination with aHER2 antibody for treating the disorders as described above may be ananti-anergic agent, such as compounds are molecules that block theactivity of CTLA-4, e.g. ipilimumab.

In one embodiment, a therapeutic agent for use in combination with aHER2 antibody for treating the disorders as described above may be ananti-cancer nucleic acid or an anti-cancer inhibitory RNA molecule.

Examples of other anti-cancer agents, which may be relevant astherapeutic agents for use in combination with a HER2 antibody fortreating the disorders as described above are differentiation inducingagents, retinoic acid analogues (such as all trans retinoic acid, 13-cisretinoic acid and similar agents), vitamin D analogues (such asseocalcitol and similar agents), inhibitors of ErbB3, ErbB4, IGF-IR,insulin receptor, PDGFRa, PDGFRbeta, Flk2, Flt4, FGFR1, FGFR2, FGFR3,FGFR4, TRKA, TRKC, RON (such as an anti-RON antibody), Sea, Tie, Tie2,Eph, Ret, Ros, Alk, LTK, PTK7 and similar agents.

Examples of other anti-cancer agents, which may be relevant astherapeutic agents for use in combination with a HER2 antibody fortreating the disorders as described above are estramustine andepirubicin.

Examples of other anti-cancer agents, which may be relevant astherapeutic agents for use in combination with a HER2 antibody fortreating the disorders as described above are a HSP90 inhibitor like17-allyl amino geld-anamycin, antibodies directed against a tumorantigen such as PSA, CA125, KSA, integrins, e.g. integrin 01, orinhibitors of VCAM.

Examples of other anti-cancer agents, which may be relevant astherapeutic agents for use in combination with a HER2 antibody fortreating the disorders as described above are calcineurin-inhibitors(such as valspodar, PSC 833 and other MDR-1 or p-glycoproteininhibitors), TOR-inhibitors (such as sirolimus, everolimus andrapamcyin). and inhibitors of “lymphocyte homing” mechanisms (such asFTY720), and agents with effects on cell signaling such as adhesionmolecule inhibitors (for instance anti-LFA).

In one embodiment, the HER2 antibody of the invention is for use incombination with one or more other therapeutic antibodies, such asofatumumab, zanolimumab, daratumumab, ranibizumab, nimotuzumab,panitumumab, hu806, daclizumab (Zenapax), basiliximab (Simulect),infliximab (Remicade), adalimumab (Humira), natalizumab (Tysabri),omalizumab (Xolair), efalizumab (Raptiva) and/or rituximab.

In another embodiment, two or more different antibodies of the inventionas described herein are used in combination for the treatment ofdisease. Particularly interesting combinations include two or morenon-blocking antibodies. Such combination therapy may lead to binding ofan increased number of antibody molecules per cell, which may giveincrease efficacy, e.g. via activation of complement-mediated lysis.

In addition to the above, other embodiments of combination therapies ofthe invention include the following:

For the treatment of breast cancer, a HER2 antibody or a therapeuticconjugate thereof, in combination with methotrexate, paclitaxel,doxorubicin, carboplatin, cyclophosphamide, daunorubicin, epirubicin,5-fluorouracil, gemcitabine, ixabepilone, mutamycin, mitoxantrone,vinorelbine, docetaxel, thiotepa, vincristine, capecitabine, an EGFRantibody (e.g. zalutumumab, cetuximab, panitumumab or nimotuzumab) orother EGFR inhibitor (such as gefitinib or erlotinib), another HER2antibody or -conjugate (such as, e.g., trastuzumab, trastuzumab-DM1 orpertuzumab), an inhibitor of both EGFR and HER2 (such as lapatinib),and/or in combination with a HER3 inhibitor.

For the treatment of non-small-cell lung cancer, a HER2 antibody incombination with EGFR inhibitors, such as an EGFR antibody, e.g.zalutumumab, cetuximab, panitumumab or nimotuzumab or other EGFRinhibitors (such as gefitinib or erlotinib), or in combination with ananother HER2 agent (such as a HER2 antibody, e.g. trastuzumab,trastuzumab-DM1 or pertuzumab) or in combination with an inhibitor ofboth EGFR and HER2, such as lapatinib, or in combination with a HER3inhibitor.

For the treatment of colorectal cancer a HER2 antibody in combinationwith one or more compounds selected from: gemcitabine, bevacizumab,FOLFOX, FOLFIRI, XELOX, IFL, oxaliplatin, irinotecan, 5-FU/LV,Capecitabine, UFT, EGFR targeting agents, such as cetuximab,panitumumab, zalutumumab; VEGF inhibitors, or tyrosine kinase inhibitorssuch as sunitinib.

For the treatment of prostate cancer a HER2 antibody in combination withone or more compounds selected from: hormonal/antihormonal therapies;such as antiandrogens, Luteinizing hormone releasing hormone (LHRH)agonists, and chemotherapeutics such as taxanes, mitoxantrone,estramustine, 5FU, vinblastine, and ixabepilone.

Radiotherapy—Surgery

In one embodiment, the present invention provides a method for treatinga disorder involving cells expressing HER2 in a subject, which methodcomprises administration of a therapeutically effective amount of a HER2antibody, such as a HER2 antibody of the present invention, andradiotherapy to a subject in need thereof.

In one embodiment, the present invention provides a method for treatingor preventing cancer, which method comprises administration of atherapeutically effective amount of a HER2 antibody, such as a HER2antibody of the present invention, and radiotherapy to a subject in needthereof.

In one embodiment, the present invention provides the use of a HER2antibody, such as a HER2 antibody of the present invention, for thepreparation of a pharmaceutical composition for treating cancer to beadministered in combination with radiotherapy.

Radiotherapy may comprise radiation or associated administration ofradiopharmaceuticals to a patient is provided. The source of radiationmay be either external or internal to the patient being treated(radiation treatment may, for example, be in the form of external beamradiation therapy (EBRT) or brachytherapy (BT)). Radioactive elementsthat may be used in practicing such methods include, e.g., radium,cesium-137, iridium-192, americium-241, gold-198, cobalt-57, copper-67,technetium-99, iodide-123, iodide-131, and indium-111.

In a further embodiment, the present invention provides a method fortreating or preventing cancer, which method comprises administration toa subject in need thereof of a therapeutically effective amount of aHER2 antibody, such as a HER2 antibody of the present invention, incombination with surgery.

Diagnostic Uses

The HER2 antibodies of the invention may also be used for diagnosticpurposes. Thus, in a further aspect, the invention relates to adiagnostic composition comprising a HER2 antibody as defined herein.

In one embodiment, the HER2 antibodies of the present invention may beused in vivo or in vitro for diagnosing diseases wherein activated cellsexpressing HER2 play an active role in the pathogenesis, by detectinglevels of HER2, or levels of cells which contain HER2 on their membranesurface. This may be achieved, for example, by contacting a sample to betested, optionally along with a control sample, with the HER2 antibodyunder conditions that allow for formation of a complex between theantibody and HER2.

Thus, in a further aspect, the invention relates to a method fordetecting the presence of HER2 antigen, or a cell expressing HER2, in asample comprising:

-   -   contacting the sample with a HER2 antibody of the invention        under conditions that allow for formation of a complex between        the antibody and HER2; and    -   analyzing whether a complex has been formed.

In one embodiment, the method is performed in vitro.

More specifically, the present invention provides methods for theidentification of, and diagnosis of invasive cells and tissues, andother cells targeted by HER2 antibodies of the present invention, andfor the monitoring of the progress of therapeutic treatments, statusafter treatment, risk of developing cancer, cancer progression, and thelike.

Suitable labels for the HER2 antibody and/or secondary antibodies usedin such techniques are well-known in the art.

In a further aspect, the invention relates to a kit for detecting thepresence of HER2 antigen, or a cell expressing HER2, in a samplecomprising

-   -   a HER2 antibody of the invention or a bispecific molecule of the        invention; and    -   instructions for use of the kit.

In one embodiment, the present invention provides a kit for diagnosis ofcancer comprising a container comprising a HER2 antibody, and one ormore reagents for detecting binding of the HER2 antibody to HER2.Reagents may include, for example, fluorescent tags, enzymatic tags, orother detectable tags. The reagents may also include secondary ortertiary antibodies or reagents for enzymatic reactions, wherein theenzymatic reactions produce a product that may be visualized.

Anti-Idiotypic Antibodies

In a further aspect, the invention relates to an anti-idiotypic antibodywhich binds to a HER2 antibody of the invention as described herein.

An anti-idiotypic (Id) antibody is an antibody which recognizes uniquedeterminants generally associated with the antigen-binding site of anantibody. An Id antibody may be prepared by immunizing an animal of thesame species and genetic type as the source of a HER2 mAb with the mAbto which an anti-Id is being prepared. The immunized animal typicallycan recognize and respond to the idiotypic determinants of theimmunizing antibody by producing an antibody to these idiotypicdeterminants (the anti-Id antibody).

An anti-Id antibody may also be used as an “immunogen” to induce animmune response in yet another animal, producing a so-calledanti-anti-Id antibody. An anti-anti-Id may be epitopically identical tothe original mAb, which induced the anti-Id. Thus, by using antibodiesto the idiotypic determinants of a mAb, it is possible to identify otherclones expressing antibodies of identical specificity.

The present invention is further illustrated by the following examples,which should not be construed as limiting the scope of the invention.

The present invention is further illustrated by the following examples,which should not be construed as limiting the scope of the invention.

EXAMPLES Example 1—Expression Constructs for HER2 and HER2 Variants

Fully codon-optimized constructs for expression of full length HER2(1255 aa, Swissprot P04626), the extracellular domain (ECD) of HER2(Her2-ECDHis, aa 1-653 with a C-terminal His6 tag), the naturallyoccurring HER2 splice variant (Her2-delex16, resulting from exon 16deletion and lacking aa 633-648) and a truncated form of the HER2receptor (Her2-stumpy, aa 648-1256), were generated. The constructcontained suitable restriction sites for cloning and an optimal Kozaksequence (Kozak, M., Gene 1999; 234(2):187-208.). The constructs werecloned in the mammalian expression vector pEE13.4 (Lonza Biologics;Bebbington, C. R., et al., Biotechnology (N Y) 1992; 10(2):169-75) andfully sequenced to confirm the correctness of the construct.

Example 2—Expression Constructs for Pertuzumab, C1 and F5

Fully codon-optimized constructs for expression of the heavy chain (HC)and the light chain (LC) of the IgG1 antibodies pertuzumab, C1 and F5 inHEK cells, were generated. The variable regions encoded by theseconstructs are identical to those described in U.S. Pat. No. 6,949,245for pertuzumab heavy chain and light chain and U.S. Pat. No. 7,244,826for C1 and F5 heavy and light chain. For C1 and F5, the mammalianexpression vectors p33G1f and p33K or p33L (pcDNA3.3 (Invitrogen))containing the fully codon optimized constant region for the human IgG1heavy chain (allotype f), the human kappa light chain or the humanlambda light chain, respectively, were used. For pertuzumab, themammalian expression vectors pG1f (pEE12.4 (Lonza Biologics) and pKappa(pEE6.4 (Lonza Biologics), containing the fully codon-optimized constantregion for the human IgG1 heavy chain (allotype f) and the human kappalight chain, respectively, were used.

Trastuzumab (Herceptin®) can be produced in the same manner, using theheavy and light chain sequences described in, e.g., U.S. Pat. No.7,632,924.

Example 3—Transient Expression in HEK-293 or CHO Cells

Freestyle™ 293-F (a HEK-293 subclone adapted to suspension growth andchemically defined Freestyle medium, (HEK-293F)) cells were obtainedfrom Invitrogen and transfected with the appropriate plasmid DNA, using293fectin (Invitrogen) according to the manufacturer's instructions. Inthe case of antibody expression, the appropriate heavy chain and lightchain expression vectors were co-expressed.

pEE13.4Her2, pEE13.4Her2-delex16 and pEE13.4Her2-stumpy were transientlytransfected in the Freestyle™ CHO—S(Invitrogen) cell line usingFreestyle MAX transfection reagent (Invitrogen). Expression of HER2 andHer2-delex16 was tested by means of FACS analysis as described below.

Example 4—Stable Polyclonal Pool Expression in NS0

pEE13.4Her2, pEE13.4Her2-delex16 and pEE13.4Her2-stumpy were stablytransfected in NS0 cells by nucleofection (Amaxa). A pool of stablytransfected cells was established after selection on glutamine dependentgrowth, based on the integrated glutamine synthetase selection marker(Barnes, L. M., et al., Cytotechnology 2000; 32(2):109-123).

Example 5—Purification of His-Tagged HER2

Her2ECDHis was expressed in HEK-293F cells. The His-tag in Her2ECDHisenabled purification with immobilized metal affinity chromatography,since the His-tagged protein binds strongly to the resin beads, whileother proteins present in the culture supernatant do not bind strongly.

In this process, a chelator fixed onto the chromatographic resin wascharged with Co²⁺ cations. Her2ECDHis containing supernatant wasincubated with the resin in batch mode (i.e. solution). Afterincubation, the beads were retrieved from the supernatant and packedinto a column. The column was washed in order to remove weakly boundproteins. The strongly bound Her2ECDHis proteins were then eluted with abuffer containing imidazole, which competes with the binding of His toCo²⁺. The eluent was removed from the protein by buffer exchange on adesalting column.

Example 6—Immunization Procedure of Transgenic Mice

Antibodies 001, 019, 021, 025, 027, 032, 033, 035, 036, 049, 050, 051,054, 055, 084, 091, 094, 098, 100, 105, 123 and 124 were derived fromthe following immunization: three female HCo12 mice, one male and twofemale HCo12-Balb/C mice, one male HCo17 mouse and one male HCo20 mouse(Medarex, San Jose, Calif., USA) were immunized alternating with 5×10⁶NS0 cells transiently transfected with Her2ECD intraperitoneal (IP) and20 μg Her2ECDHis protein coupled to the hapten Keyhole Limpet Hemocyanin(KLH) subcutaneous (SC) at the tail base, with an interval of fourteendays. A maximum of eight immunizations was performed per mouse (four IPand four SC immunizations). The first immunization with cells was donein complete Freunds' adjuvant (CFA; Difco Laboratories, Detroit, Mich.,USA). For all other immunizations, cells were injected IP in PBS and KLHcoupled Her2ECD was injected SC using incomplete Freunds' adjuvant (IFA;Difco Laboratories, Detroit, Mich., USA).

Antibodies 125, 127, 129, 132, 152, 153 and 159 were derived from thefollowing immunization: one male and two female HCo12-Balb/C mice, onefemale HCo20 mouse, and one female HCo12 mouse (Medarex) were immunizedalternating with 5×10⁶ NS0 cells transiently transfected withHer2delex16 IP and 20 μg Her2ECDHis protein coupled to the haptenKeyhole Limpet Hemocyanin (KLH) SC at the tail base, with an interval offourteen days. A maximum of eight immunizations was performed per mouse(four IP and four SC immunizations). The first immunization with cellswas done in complete Freunds' adjuvant (CFA; Difco Laboratories,Detroit, Mich., USA). For all other immunizations, cells were injectedIP in PBS and KLH coupled Her2ECD was injected SC using incompleteFreunds' adjuvant (IFA; Difco Laboratories, Detroit, Mich., USA).

Antibody 143, 160, 161, 162, 166 and 169 were derived from the followingimmunization: one female and one male Hco12 mouse, one femaleHco12-Balb/C mouse, one male HCo17 mouse and one male HCo20 mouse(Medarex) were immunized alternating with 20 μg Her2ECDHis proteincoupled to the hapten Keyhole Limpet Hemocyanin (KLH), alternating IPand SC at the tail base with an interval of fourteen days. A maximum ofeight immunizations was performed per mouse (four IP and four SCimmunizations). The first immunization was done IP in complete Freunds'adjuvant (CFA; Difco Laboratories, Detroit, Mich., USA). The otherimmunizations were injected using incomplete Freunds' adjuvant (IFA;Difco Laboratories, Detroit, Mich., USA).

Mice with at least two sequential titers against TC1014-Her2,TC1014-Her2delex16 or TC1014-Her2stumpy in the antigen specific FMATscreening assay (as described in example 7), were considered positiveand fused.

Example 7—Homogeneous Antigen Specific Screening Assay

The presence of HER2 antibodies in sera of immunized mice or HuMab(human monoclonal antibody) hybridoma or transfectoma culturesupernatant was determined by homogeneous antigen specific screeningassays (four quadrant) using Fluorometric Micro volume Assay Technology(FMAT; Applied Biosystems, Foster City, Calif., USA). For this, acombination of 4 cell based assays was used. Binding to TC1014-Her2(HEK-293F cells transiently expressing the HER2 receptor; produced asdescribed above), TC1014-Her2delex16 (HEK-293F cells transientlyexpressing the extracellular domain of Her2-delex (a 16 amino aciddeletion mutant of the HER2 receptor; produced as described above) andTC1014-Her2stumpy (HEK-293F cells transiently expressing theextracellular stumpy domain of the HER2 receptor; produced as describedabove) as well as HEK293 wild type cells (negative control cells whichdo not express HER2) was determined. Samples were added to the cells toallow binding to HER2. Subsequently, binding of HuMab was detected usinga fluorescent conjugate (Goat anti-Human IgG-Cy5; JacksonImmunoResearch). TH1014-Pertuzumab (produced in HEK-293F cells) was usedas a positive control and HuMab-mouse pooled serum and HuMab-KLH wereused as negative controls. The samples were scanned using an AppliedBiosystems 8200 Cellular Detection System (8200 CDS) and‘counts×fluorescence’ was used as read-out. Samples were stated positivewhen counts were higher than 50 and counts×fluorescence were at leastthree times higher than the negative control.

Example 8—HuMab Hybridoma Generation

HuMab mice with sufficient antigen-specific titer development (definedas above) were sacrificed and the spleen and lymph nodes flanking theabdominal aorta and vena cava were collected. Fusion of splenocytes andlymph node cells to a mouse myeloma cell line was done by electrofusionusing a CEEF 50 Electrofusion System (Cyto Pulse Sciences, Glen Burnie,Md., USA), essentially according to the manufacturer's instructions.Next, the primary wells were sub cloned using the ClonePix system(Genetix, Hampshire, UK). To this end specific primary well hybridoma'swere seeded in semisolid medium made from 40% CloneMedia (Genetix,Hampshire, UK) and 60% HyQ 2× complete media (Hyclone, Waltham, USA).The sub clones were retested in the antigen-specific binding assay asdescribed in Example 7 and IgG levels were measured using an Octet(Fortebio, Menlo Park, USA) in order to select the most specific andbest producing clone per primary well for further expansion. Furtherexpansion and culturing of the resulting HuMab hybridomas were donebased upon standard protocols (e.g. as described in Coligan J. E.,Bierer, B. E., Margulies, D. H., Shevach, E. M. and Strober, W., eds.Current Protocols in Immunology, John Wiley & Sons, Inc., 2006). Clonesderived by this process were designated PC1014.

Example 9—Mass Spectrometry of Purified Antibodies

Small aliquots of 0.8 mL antibody containing supernatant from 6-well orHyperflask stage were purified using PhyTip columns containing Protein Gresin (PhyNexus Inc., San Jose, USA) on a Sciclone ALH 3000 workstation(Caliper Lifesciences, Hopkinton, USA). The PhyTip columns were usedaccording to manufacturer's instructions, although buffers were replacedby: Binding Buffer PBS (B.Braun, Medical B.V., Oss, Netherlands) andElution Buffer 0.1M Glycine-HCl pH 2.7 (Fluka Riedel-de Haën, Buchs,Germany). After purification, samples were neutralized with 2M Tris-HCl,pH 9.0 (Sigma-Aldrich, Zwijndrecht, Netherlands). Alternatively, in somecases larger volumes of culture supernatant were purified usingMabSelect SuRe.

After purification, the samples were placed in a 384-well plate (Waters,100 μl square well plate, part #186002631). Samples were deglycosylatedovernight at 37° C. with N-glycosidase F (Roche cat no 11365177001. DTT(15 mg/mL) was added (1 μL/well) and incubated for 1 h at 37° C. Samples(5 or 6 μL) were desalted on an Acquity UPLC™ (Waters, Milford, USA)with a BEH300 C18, 1.7 μm, 2.1×50 mm column at 60° C. MQ water and LC-MSgrade acetonitrile (Biosolve, cat no 01204101, Valkenswaard, TheNetherlands) with both 0.1% formic acid (Fluka, cat no 56302, Buchs,Germany), were used as Eluens A and B, respectively. Time-of-flightelectrospray ionization mass spectra were recorded on-line on amicrOTOF™ mass spectrometer (Bruker, Bremen, Germany) operating in thepositive ion mode. Prior to analysis, a 900-3000 m/z scale wascalibrated with ES tuning mix (Agilent Technologies, Santa Clara, USA).Mass spectra were deconvoluted with DataAnalysis™ software v. 3.4(Bruker) using the Maximal Entropy algorithm searching for molecularweights between 5 and 80 kDa.

After deconvolution, the resulting heavy and light chain masses for allsamples were compared in order to find duplicate antibodies. This wassometimes due to the presence of an extra light chain, but in thecomparison of the heavy chains, the possible presence of C-terminallysine variants was also taken into account. This resulted in a list ofunique antibodies, i.e., a unique combination of specific heavy andlight chains. In case duplicate antibodies were found, one uniqueantibody was selected based on results from other tests.

Example 10—Sequence Analysis of the HER2 Antibody Variable Domains andCloning in Expression Vectors

Total RNA of the HER2 HuMabs was prepared from 5×10⁶ hybridoma cells and5′-RACE-Complementary DNA (cDNA) was prepared from 100 ng total RNA,using the SMART RACE cDNA Amplification kit (Clontech), according to themanufacturer's instructions. VH and VL coding regions were amplified byPCR and cloned directly, in frame, in the pG1f and pKappa expressionvectors, by ligation independent cloning (Aslanidis, C. and P. J. deJong, Nucleic Acids Res 1990; 18(20): 6069-74). Clones derived by thisprocess were designated TH1014. For each antibody, 16 VL clones and 8 VHclones were sequenced. Clones which predicted heavy and light chain massin agreement with the mass of the hybridoma derived material of the sameantibody (as determined by mass spectrometry) were selected for furtherstudy and expression.

The resulting sequences are shown in FIGS. 1 and 2 and in the SequenceListing. Selected sequences are also described in more detail below. CDRsequences were defined according to IMGT (Lefranc M P. et al., NucleicAcids Research, 27, 209-212, 1999 and Brochet X. Nucl. Acids Res. 36,W503-508 (2008)). Table 1, Table 2 and Table 3 give an overview ofantibody sequence information or germline sequences, and Table 4 showsconsensus sequences.

TABLE 1 Heavy chain variable region (VH), light chainvariable region (VL) and CDR sequences ofHuMabs 169, 050, 084, 025, 091, 129, 127, 159, 098, 153, and 132.SEQ ID No: 1 VH 169 QVQLVQSGAEVKKPG ASVKVSCKASGYTFT NYGISWVRQAPGQGLEWMGWLSAYSGNTIY AQKLQGRVTMTTDTS TTTAYMELRSLRSDD TAVYYCARDRIVVRPDYFDYWGQGTLVTVS S SEQ ID No: 2 VH 169, CDR1 GYTFTNYG SEQ ID No: 3VH 169, CDR2 LSAYSGNT SEQ ID No: 4 VH 169, CDR3 ARDRIVVRPDYFDYSEQ ID No: 5 VL 169 EIVLTQSPATLSLSP GERATLSCRASQSVS SYLAWYQQKPGQAPRLLIYDASNRATGIPA RFSGSGSGTDFTLTI SSLEPEDFAVYYCQQ RSNWPRTFGQGTKVE IKSEQ ID No: 6 VL 169, CDR1 QSVSSY VL 169, CDR2 DAS SEQ ID No: 7VL 169, CDR3 QQRSNWPRT SEQ ID No: 8 VH 050 EVQLLESGGGLVQPGGSLRLSCAASGFTFS SYAMNWVRQAPGKGL EWVSAISGRGGTTYY ADSVKGRFTISRDNSKNTLYLQMSSLRAED TAVYYCAKARANWDY FDYWGQGTLVTVSS SEQ ID No: 9 VH 050, CDR1GFTFSSYA SEQ ID No: 10 VH 050, CDR2 ISGRGGTT SEQ ID No: 11 VH 050, CDR3AKARANWDYFDY SEQ ID No: 12 VL 050 DIQMTQSPSSVSASV GDRVTITCRASQGISSWLAWYQHKPGKAPK LLIYAASILQSGVPS RFSGSGSGTDFTLTI SSLQPEDFATYYCQQANSFPITFGQGTRLE IK SEQ ID No: 13 VL 050, CDR1 QGISSW VL 050, CDR2 AASSEQ ID No: 14 VL 050, CDR3 QQANSFPIT SEQ ID No: 15 VH 084QVQLVQSGAEVKKPG SSVKVSCKASGGTFR TYAINWVRQAPGQGL EWMGRINTVLGIVNHAQKFQGRVTITADKS TNTAYMELNSLRSED TAVYYCAREKGVDYY YGIEVWGQGTTVTVS SSEQ ID No: 16 VH 084, CDR1 GGTFRTYA SEQ ID No: 17 VH 084, CDR2 INTVLGIVSEQ ID No: 18 VH 084, CDR3 AREKGVDYYYGIEV SEQ ID No: 19 VL 084DIQMTQSPSSVSASV GDRVTITCRASQGIS SWLAWYQHKPGKAPK LLIYVASTLQSGVPSRFSGSGSGTDFTLTI SSLQPEDFATYYCQQ ANSFPLTFGGGTKVE IK SEQ ID No: 20VL 084, CDR1 QGISSW VL 084, CDR2 VAS SEQ ID No: 21 VL 084, CDR3QQANSFPLT SEQ ID No: 22 VH 025 QVQLQQWGAGLLKPS ETLSLTCAVYGGSFSDYYWNWIRQPPGKGL EWIGEIHHSGSTNYN PSLKSRVTISVDTSK NQFSLKLSSVTAADTAVYYCARGYYDSGVY YFDYWAQGTLVTVSS SEQ ID No: 23 VH 025, CDR1 GGSFSDYYSEQ ID No: 24 VH 025, CDR2 IHHSGST SEQ ID No: 25 VH 025, CDR3ARGYYDSGVYYFDY SEQ ID No :26 VL 025 DIQMTQSPSSLSASV GDRVTITCRASQGISRWLAWYQQKPEKAPK SLIYAASSLRSGVPS RFSGSGSGTDFTLTI SSLQPEDFATYYCQQYNSYPITFGQGTRLE IK SEQ ID No: 27 VL 025, CDR1 QGISRW VL 025, CDR2 AASSEQ ID No: 28 VL 025, CDR3 QQYNSYPIT SEQ ID No: 29 VH 091QVQLQQWGAGLLKPS ETLSLTCAVSGGSFS GYYWTWIRQPPGKGL EWIGEIYHSGDTNYNPSLKSRVTISVDTSK NQFSLKLYSVTAADT AVYYCARLYFGSGIY YLDYWGQGTLVTVSSSEQ ID No: 30 VH 091, CDR1 GGSFSGYY SEQ ID No: 163 VH 091, CDR2 IYHSGDTSEQ ID No: 31 VH 091, CDR3 ARLYFGSGIYYLDY SEQ ID No: 32 VL 091DIQMTQSPSSLSASV GDRVTITCRASQGIS SWLVWYQQKPEKAPK SLIYAASSLQSGVPSRFSGSGSGTDFTLTI SSLQPEDFATYYCQQ YNSFPPTFGQGTKVE IK SEQ ID No: 33VL 091, CDR1 QGISSW VL 091, CDR2 AAS SEQ ID No: 34 VL 091, CDR3QQYNSFPPT SEQ ID No: 35 VH 129 QVQLVESGGGVVQPG RSLRLSCAASGFTFSTFAIHWVRQAPGKGL EWVAVISYDGGHKFY ADSVKGRFTISRDNS KNTLYLQMNSLRAEDTAMYYCARGLGVWGA FDYWGQGTLVTVSS SEQ ID No: 36 VH 129, CDR1 GFTFSTFASEQ ID No: 37 VH 129, CDR2 ISYDGGHK SEQ ID No: 38 VH 129, CDR3ARGLGVWGAFDY SEQ ID No :39 VL 129 EIVLTQSPATLSLSP GERATLSCRASQSVSSYLAWYQQKPGQAPR LLIYDASNRATGIPA RFSGSGSGTDFTLTI SSLEPEDFAVYYCQQRSNWWTFGQGTKVEI K SEQ ID No: 40 VL 129, CDR1 QSVSSY VL 129, CDR2 DASSEQ ID No: 41 VL 129, CDR3 QQRSNWWT SEQ ID No: 42 VH 127 EVQLVQSGAEVKKPGESLTISCKGSGYSFS IYWIGWVRQMPGKGL EWMGIIFPGDSDIRY SPSFQGQVTISADKSISTAYLQWSSLKASD TAMYYCARQPGDWSP RHWYFDLWGRGTLVT VSS SEQ ID No: 43VH 127, CDR1 GYSFSIYW SEQ ID No: 44 VH 127, CDR2 IFPGDSDI SEQ ID No: 45VH 127, CDR3 ARQPGDWSPRHWYFDL SEQ ID No: 46 VL 127 VIWMTQSPSLLSASTGDRVTISCRMSQGIS SYLAWYQQKPGKAPE LLIYAASTLQSGVPS RFSGSGSGTDFTLTISYLQSEDFATYYCQQ YYSFPLTFGGGTKVE IK SEQ ID No: 47 VL 127, CDR1 QGISSYVL 127, CDR2 AAS SEQ ID No: 48 VL 127, CDR3 QQYYSFPLT SEQ ID No: 49VH 159 EVQLVQSGAEVKKPG ESLKISCKGSGYNFT SYWIGWVRQMPGKGL EWMGIIYPGDSDTRYSPSFQGQVTISADKS ISTAYLQWSSLKASD TAMYYCARWGTYYDI LTGYFNWFDPWGQGT LVTVSSSEQ ID No: 50 VH 159, CDR1 GYNFTSYW SEQ ID No: 51 VH 159, CDR2 IYPGDSDTSEQ ID No: 52 VH 159, CDR3 ARWGTYYDILTGYFN SEQ ID No: 53 VL 159DIQMTQSPSSLSASV GDRVTITCRASQGIS SWLAWYQQKPEKAPK SLIYAASSLQSGVPSRFSGSGSGTDFTLTI SSLQPEDFATYYCQQ YYIYPWTFGQGTKVE IK SEQ ID No: 54VL 159, CDR1 QGISSW VL 159, CDR2 AAS SEQ ID No: 55 VL 159, CDR3QQYYIYPWT SEQ ID No: 56 VH 098 EVQLLESGGGLVQPG GSLRLSCAASGFTFSNYGMSWVRQAPGKGL EWVSAISGSAYSTYY ADSVKGRFTISRDNS KNTLWLQMNSLRAEDTAVYYCAKAHYHGSG SYYTLFDYWGQGTLV TVSS SEQ ID No: 57 VH 098, CDR1 GFTFSNYGSEQ ID No: 58 VH 098, CDR2 ISGSAYST SEQ ID No: 59 VH 098, CDR3AKAHYHGSGSYYTLFDY SEQ ID No: 60 VL 098 DIQMTQSPSSLSASV GDRVTITCRASQGISSWLAWYQQKPEKAPK SLIYAASSLQSGVPS RFSGSGSGTDFTLTI SSLQPEDFATYYCQQYNSYPYTFGQGTKLE IK SEQ ID No: 61 VL 098, CDR1 QGISSW VL 098, CDR2 AASSEQ ID No: 62 VL 098, CDR3 QQYNSYPYT SEQ ID No: 63 VH 153QVQLVESGGGVVQPG RSLRLSCAASGFTFS DYVIHWVRQAPGKGL EWVTVISYDGSNKYYADSVKGRFTISRDNS KNTLYLQMNSLSAED TAMYYCARGGITGTT GVFDYWGQGTLVTVS SSEQ ID No: 64 VH 153, CDR1 GFTFSDYV SEQ ID No: 65 VH 153, CDR2 ISYDGSNKSEQ ID No: 66 VH 153, CDR3 ARGGITGTTGVFDY SEQ ID No: 67 VL 153DIQMTQSPSSLSASV GDRVTITCRASQGIS SWLAWYQQKPEKAPK SLIYDASSLQSGVPSRFSGSGYGTDFSLTI SSLQPEDFAIYYCQQ YKSYPITFGQGTRLE IK SEQ ID No: 68VL 153, CDR1 QGISSW VL 153, CDR2 DAS SEQ ID No: 69 VL 153, CDR3QQYKSYPIT SEQ ID No: 70 VH 132 QVQLVQSGAEVKKPG ASVKVSCKASGYTFTSYGISWVRQAPGQGL EWMGWISAYNGNSNY VQKFQGRVTMTTDTT TSTAYMELRSLTSDDTAVYYCAREYSYDSG TYFYYGMDVWGQGTT VTVSS SEQ ID No: 71 VH 132, CDR1GYTFTSYG SEQ ID No: 72 VH 132, CDR2 ISAYNGNS SEQ ID No: 73 VH 132, CDR3AREYSYDSGTYFYYG MDV SEQ ID No: 74 VL 132 EIVLTQSPATLSLSP GERATLSCRASQSVSSYLAWYQQKPGQAPR LLIYDASNRATGIPA RFSGSGSGTDFTLTI SSLEPEDFAVYYCQQRSNWPMYTFGQGTKL EIK SEQ ID No: 75 VL 132, CDR1 QSVSSY VL 132, CDR2 DASSEQ ID No: 76 VL 132, CDR3 QQRSNWPMYT

TABLE 2 Mouse origin and heavy and light chain sequence homologies ofselected HuMabs. HuMab: Mouse: Strain: Germline VH: Germline VL: 169361494 HCo20 IgHV1-18-01 IgKV3-11-01 050 350633 HCo12 IgHV3-23-01IgKV1-12-01 084 350615 HCo12-BalbC IgHV1-69-04 IgKV1-12-01 025 350631HCo12 IgHV4-34-01 IgKV1D-16-01 091 350630 HCo12 IgHV4-34-01 IgKV1D-16-01129 359783 HCo12-BalbC IgHV3-30-3-01 IgKV3-11-01 127 359783 HCo12-BalbCIgHV5-51-01 IgKV1D-8-01 159 363503 HCo12 IgHV5-51-01 IgKV1D-16-01 098350659 HCo17 IgHV3-23-01 IgKV1D-16-01 153 359785 HCo12-BalbCIgHV3-30-3-01 IgKV1D-16-01 132 361487 HCo20 IgHV1-18-01 IgKV3-11-01

TABLE 3 Heavy chain variable region (VH), light chainvariable region (VL) sequences of HuMabs 049,051, 055, 123, 161, 124, 001, 143, 019, 021,027, 032, 035, 036, 054, 094. The respective CDRs correspond to thoseunderlined in FIGS. 1 and 2, for VH and VL sequences, respectively.SEQ ID No: 77 VH 049 EVQLLESGGDLVQPG GSLRLSCAASGFTFS SYAMSWVRQAPGKGLEWVSAISGRGGTTYY ADSVKGRFTISRDNS KSTLCLQMNSLRAED TAVYYCAKARANWDYFDYWGQGTLVTVSS SEQ ID No: 78 VL 049 DIQMTQSPSSVSASV GDRVTITCRASQGISSWLAWYQHKPGKAPK LLIYAASILQSGVPS RFSGSGSGTDFTLTI SSLRPEDFATYYCQQANSFPITFGQGTRLE IK SEQ ID No: 79 VH 051 EVQLLESGGDLVQPG GSLRLSCAASGFTFSSYAMSWVRQAPGKGL EWVSAISGRGGTTYY ADSVKGRFTISRDNS KSTLCLQMNSLRAEDTAVYYCAKARANWDY FDYWGQGTLVTVSS SEQ ID No: 80 VL 051 DIQMTQSPSSVSASVGDRVTITCRASQGIS SWLAWYQHKPGKAPK LLIYAASILQSGVPS RFSGSGSGTDFTLTISSLRPEDFATYYCQQ ANSFPITFGQGTRLE IK SEQ ID No: 81 VH 055 EVQLLESGGGLVQPGGSLRLSCAASGFTFS SYAMNWVRQAPGKGL EWVSAISGRGGTTYY ADSVKGRFTISRDNSKSTLCLQMNSLRAED TAVYYCAKARANWDY FDYWGQGTLVTVSS SEQ ID No: 82 VL 055DIQMTQSPSSVSASV GDRVTITCRASQGIS SWLAWYQHKPGKAPK LLIYAASILQSGVPSRFSGSGSGTDFTLTI SSLRPEDFATYYCQQ ANSFPITFGQGTRLE IK SEQ ID No: 83 VH 123QVQLVQSGAEVKKPG ASVKVSCKAAGYTFT NYGISWVRQAPGQAL EWMGWITTYSSNTIYAQKLQGRVTMTTDTS TSTAYMELRSLRSDD TAVYYCARDRVVVRP DYFDYWGQGTLVTVS SSEQ ID No: 84 VL 123 EIVLTQSPATLSLSP GERATLSCRASQSVS SYLAWYQQKPGQAPRLLIYDTSNRATGIPA RFSGSGSGTDFTLTI SSLEPEDFAVYYCQQ RSHWPRTFGQGTKVE IKSEQ ID No: 85 VH 161 QVQLVQSGAEVKKPG ASVKVSCKASGYTFT NYGISWVRQAPGQGLEWMGWLSAYSGNTIY AQKLQGRVTMTTDTS TTTAYMELRSLRSDD TAVYYCARDRIVVRPDYFDYWGQGTLVTVS S SEQ ID No: 86 VL 161 EIVLTQSPATLSLSP GERATLSCRASQSVSSYLAWYQQKPGQAPR LLIYDASNRATGIPA RFSGSGSGTDFTLTI SSLEPEDFAVYYCQQRSNWPRTFGQGTKVE IK SEQ ID No: 87 VH 124 QVQLVQSGAEVKKPG ASVKVSCKAAGYTFTNYGISWVRQAPGQGL EWMGWIITYNGNTIY AQRFQDRVTMTTDTS TSTAYMELRSLRSDDTAVYYCARDRIIVRP DYFDYWGQGTLVTVS S SEQ ID No: 88 VL 124 EIVLTQSPATLSLSPGERATLSCRASQSVS SYLAWYQQKPGQAPR LLIYDASNRATGIPA RFSGSGSGTDFTLTISSLEPEDFAVYYCQQ RSNWPRTFGQGTKVE IK SEQ ID No: 89 VH 001 QVQLQQWGAGLLKPSETLSLTCAVYGGSFS GYYWNWIRQPPGKGL EWIGEINHSGSTNYN PSLKSRVTISVDTSKNQFSLKLSSVTAADT AVYYCARGNYGSGYY YFDLWGRGTQVTVSS SEQ ID No: 90 VL 001DIQMTQSPSSLSASV GDRVTITCRASQGIS SWLAWYQQKPEKAPK SLIFAASSLQSGVPSRFSGSGSGTDFTLTI SSLQPEDFATYYCQQ YISFPITFGQGTRLE IK SEQ ID No: 91 VH 143QVQLQQWGAGLLKPS ETLSLTCAVYGGSFS GYYWNWIRQPPGKGL EWIGEIHHSGSANYNPSLMSRVTISVDTSK NQFSLQLSSVTAADT AVYYCARGYYGSGYY YFDYWGQGTLVTVSSSEQ ID No: 92 VL 143 DIQMTQSPSSLSASV GDRVTITCRASQGIS SWLAWYQQKPEKAPKSLIYAASRLQSGVPS RFSGSGSGTDFTLTI SSLQPEDFATYYCQQ YNSYPITFGQGTRLE IKSEQ ID No: 93 VH 019 QVQLQQWGAGLLKPS ETLSLTCAVYGGSFS DYYWNWIRQPPGKGLEWIGEIHHVGSTNYN PSLKSRVTISVDTSK SQFSLKLSSVTAADT AVYYCARGYYDSGVYYFDYWAQGTLVTVSS SEQ ID No: 94 VL 019 DIQMTQSPSSLSASV GDRVTITCRASQGISRWLAWYQQKPEKAPK SLIYAASSLRSGVPS RFSGSGSGTDFTLTI SSLQPEDFATYYCQQYNSYPITFGQGTRLE IK SEQ ID No: 95 VH 021 QVQLQQWGAGLLKPS ETLSLTCAVYGGSFSDYYWNWIRQPPGKGL EWIGEIHHSGSTNYN PSLKSRVTISVDTSK NQFSLKLSSVTAADTAVYYCARGYYASGVY YFDYWGQGTLVTVSS SEQ ID No: 96 VL 021 DIQMTQSPSSLSASVGDRVTITCRASQGIS SWLAWYQQKPEKAPK SLIYAASSLQSGVPS RFSGSGSGTDFTLTISSLQPEDFATYYCQQ YNSYPITFGQGTRLE IK SEQ ID No: 97 VH 027 QVQLQQWGAGLLKPSETLSLTCAVYGGSFS DYFWNWIRQPPGKGL EWIGEIHHSGSTNYN PSLKSRVTISVDTSKNQFSLNLSSVTAADT AVYYCARGLIGSGYY YFDYWDQGTLVTVSS SEQ ID No: 98 VL 027DIQMTQSPSSLSASV GDRVTITCRASQGIS SWLAWYQQKPEKAPK SLIYAASSLQSGVPSRFSGSGSGTDFTLTI SSLQPEDFATYYCQQ YNSYPITFGQGTRLE IK SEQ ID No: 99 VH 032QVQLQQWGAGLLKPS ETLSLTCAVYGGSFS GYYWSWIRQPPGKGL EWIGEINHSGDTNYNPSLTSRVTISVDTSK NQFSLKLSSVTAADT AVYYCARLFYGSGIY YFDYWGQGTLVTVSSSEQ ID No: 100 VL 032 DIQMTQSPSSLSASV GDRVTITCRASQGIS SWLAWYQQKPEKAPKSLIYATFRLQSGVPS RFSGSGSGTDFTLTI SSLQPEDFATYYCQQ YNSFPPTFGQGTKVE IKSEQ ID No: 101 VH 035 QVQLQQWGAGLLKPS ETLSLTCAIYGGSFS GYYWSWIRQPPGKGLEWIGEINHSGDTNYN PSLTSRVTISVDTSK NQFSLKLSSVTAADT AVYYCARLFYGSGIYYFDYWGQGTLVTVSS SEQ ID No: 102 VL 035 DIQMTQSPSSLSASV GDRVTITCRASQGISSWLAWYQQKPEKAPK SLIYATFRLQSGVPS RFSGSGSGTDFTLTI SSLQPEDFATYYCQQYNSFPPTFGQGTKVE IK SEQ ID No: 103 VH 036 QVQLQQWGAGLLKPS ETLSLTCAVYGGSFSDYYWSWIRQPPGKGL EWIGEINHSGSTNYN PSLKSRVTISVDTSK NQFSLKLSSVTAADTAVYYCARLYYGSGTY YFDYWGQGTLVTVSS SEQ ID No: 104 VL 036 DIQMTQSPSSLSASVGDRVTITCRASQGIS SWLTWYQQKPEKAPK SLIYAASRLQSGVPS RFSGSGSGTDFTLTISSLQPEDFATYYCQQ YNSFPPTFGQGTKVE IK SEQ ID No: 105 VH 054 QVQLQQWGAGLLKPSETLSLTCAVYGGSFS GYYWSWIRQPPGKGL EWIGEIHHSGSTNYN PSLKSRVTISVDTSKNQFSLKLSSVTAADT AVYYCARLWYGSGSY YFDYWGQGTLVTVSS SEQ ID No: 106 VL 054DIQMTQSPSSLSASV GDRVTITCRASQGIS SWLAWYQQKPEKAPK SLIYAASSLQSGVPSRFSGSGSGTDFTLTI SSLQPEDFATYYCQQ YNSFPPTFGGGTKVE IK SEQ ID No: 107 VH 094QVQLQQWGAGLLKPS ETLSLTCAVSGGSFS GYYWTWIRQPPGKGL EWIGEIYHSGDTNYNPSLKSRVTISVDTSK NQFSLKLYSVTAADT AVYYCARLYFGSGIY YLDYWGQGTLVTVSSSEQ ID No: 108 VL 094 DIQMTQSPSSLSASV GDRVTITCRASQGIS SWLVWYQQKPEKAPKSLIYAASSLQSGVPS RFSGSGSGTDFTLTI SSLQPEDFATYYCQQ YNSFPPTFGQGTKVE IKSEQ ID No: 109 VH 105 EVQLLESGGGLVQPG GSLRLSCAASGFTFS NYGMSWVRQAPGKGLEWVSAISGSAYSTYY ADSVKGRFTISRDNS KNTLWLQMNSLRAED TAVYYCAKAHYHGSGSYYTLFDYWGQGTLV TVSS SEQ ID No: 110 VL 105 DIQMTQSPSSLSASVGDRVTITCRASQGIS SWLAWYQQKPEKAPK SLIYAASSLQSGVPS RFSGSGSGTDFTLTISSLQPEDFATYYCQQ YNSYPYTFGQGTKLE IK SEQ ID No: 111 VH 100 EVQLLESGGGLVQPGGSLRLSCAASGFTFN NYGMNWVRQAPGKGL EWVSAISGTGYSTYY ADSVKGRFTISRDNSKNTLYLQMNSLRAED TAVYYCAKAHYFGSG SYYTLFDYWGQGTLV TVSS SEQ ID No: 112VL 100 DIQMTQSPSSLSASV GDRVTITCRASQGIS SWLAWYQQKPEKAPK SLIYAASSLQSGVPSRFSGSGSGTDFTLTI SSLQPEDFATYYCQQ YNSYPYTFGQGTKLE IK SEQ ID No: 113 VH 125EVQLLESGGGLVQPG GSLRLSCAASGFTFT DYAMNWVRQAPGKGL EWVSTISGSGYATYYADSVKGRFTISRDNS KTTLYLQMNSLRAED TAVYYCAKGHTLGSG SYYTLFDYWGQGTLV TVSSSEQ ID No: 114 VL 125 DIQMTQSPSSLSASV GDRVTITCRASQGIN SWLAWYQQKPEKAPKSLIYAASSLQSGVPS RFSGSGSGTDFTLTI SSLQPEDFATYYCQQ YNSYPYTFGQGTKLE IKSEQ ID No: 115 VH 162 EVQLWESGGGSVQPG GSLRLSCAASGFTFS SYGMSWVRQAPGKGLEWVSGISGSGYSTYY ADSVKGRFTISRDNS KNTLYLQMNSLRAED TAVYYCAKGYYHGSGSYYTSFDYWGQGTLV TVSS SEQ ID No: 116 VL 162 DIQMTQSPSSLSASVGDRVTITCRASQGIS SWLAWYQQKPEKAPK SLIYAASSLQSGVPS RFSGSGSGTDFTLTISSLQPEDFATYYCQQ YNSYPLTFGGGTKVE IK SEQ ID No: 117 VH 033 QVQLVESGGGVVQTGRSLRLSCAASGFTFS SHAMHWVRQAPGKGL EWVAAISYDGSNKYY ADSVKGRFTISRDNSKNTLYLQMNSLRAED TAVYYCARGDYISSS GVFDYWGQGTLVTVS S SEQ ID No: 118 VL 033DIQMTQSPSSLSASV GDRVTITCRASQGIS SWLAWYQQKPEKAPK SLIYAASSLQSGVPSRFSGSGSGTDFTLTI SSLQPEDFATYYCQQ YNSYPITFGQGTRLE IK SEQ ID No: 119 VH 160QVQLVESGGGVVQPG RSLRLSCAASGFTFS SHAMHWVRQAPGKGL EWVAAISYDGSNKYYADSVKGRFTISRDNS KNTMYLQMNSLRAED TAMCYCARGSITGST GVFDYWGQGTLVTVS SSEQ ID No: 120 VL 160 DIQMTQSPSSLSASV GDRVTITCRASQDIS SWLAWYQQKPEKAPKSLIYAASSLQSGVPS RFSGSGSGTDFTLTI SSLQPEDFATYYCQQ YNSYPITFGQGTRLE IKSEQ ID No: 121 VH 166 QVQLVESGGGVVQPG RSLRLSCAASGFTFS SYAMHWVRQAPGKGLEWVAVISYDGSNEYY ADSVKGRFTISRDNS KNTLYLQMNSLRAED TAVYYCARGSIIGSTGVFDYWGQGTLVTVS S SEQ ID No: 122 VL 166 DIQMTQSPSSLSASV GDRVTITCRASQGISNWLAWYQQKPEKAPK SLIYDASSLQSGVPS RFSGSGSGTDFTLTI SSLQPEDFATYYCQQYNSYPITFGQGTRLE IK SEQ ID No: 123 VH 152 QVQVVESGGGVVQPG RSLRLSCAASGFTFSSYAMHWVRQAPGKGL EWVAVISYDGSYKYY ADSVKGRFTISRDNS KNTLYLQMNSLRAEDTAVYYCARGSITGST GVFDYWGQGTLVTVS S SEQ ID No: 124 VL 152 DIQMTQSPSSLSASVGDRVTITCRASQGIN SWLAWYQQKPEKAPK SLIYDASSLQSGVPS RFSGSGSGTDFTLTISSLQPENFATYYCQQ YNSYPITFGQGTRLE IK SEQ ID No: 125 VH 167 QVQLVESGGGVVQPGRSLRLSCAASGFTFS SYAIHWVRQAPGKGL EWVAVISYDGSNKYY ADSVKGRFTISRDNSKNTLYLQMNSLRAED TAVYYCARGSITGST GVFDYWGQGTLVTVS S SEQ ID No: 126 VL 167DIQMTQSPSSLSASV GDRVTITCRASQGIS NWLAWYQQKPEKAPK SLIYDASSLQSGVPSRFSGSGSGTDFTLTI SSLQPEDFATYYCQQ YNSYPITFGQGTRLE IK

TABLE 4Consensus CDRs based on sequence alignments shown in FIGS. 1 and 2.SEQ ID No: 9 IgHV3-23-1 VH GFTFSSYA 050-049-051- CDR1 055 SEQ ID No: 127IgHV3-23-1 VH ISGX1GGX2T Wherein X1 = R or S, 050-049-051- CDR2 and 055X2 = T or S; preferably, wherein X1 = R and X2 = T SEQ ID No: 11IgHV3-23-1 VH AKARANWDYFD 050-049-051- CDR3 Y 055 SEQ ID No: 128IgHV1-69-04 VH GGTFX1X2YA Wherein X1 = R or S, 084 CDR1 and X2 = T or S;preferably, wherein X1 = R and X2 = T SEQ ID No: 129 IgHV1-69-04 VHIX2X3X3LGIX4 Wherein X1 = N or I, 084 CDR2 X2 = T or P, X3 = V or I, andX4 = V or A, preferably, wherein X1 = N, X2 = T, X3 = V, and X4 = VSEQ ID No: 130 IgHV1-69-04 VH AREKGVDYYYG Wherein X1 = I or M, 084 CDR3X1X2 X2 = E or D; preferably, wherein X1 = I, X2 = E SEQ ID No: 131IgHV1-18-1 VH GYTFTXYG Wherein X = N or S, 169-123-161- CDR1 preferably124 N SEQ ID No: 132 IgHV1-18-1 VH IX1X2YX3GNT Wherein X1 = S,169-123-161- CDR2 T, or I; 124 X2 = A or T; X3 = S or N; preferably,wherein X1 = S, X2 = A, and X3 = S SEQ ID No: 133 IgHV1-18-1 VHARDRX1X2VRP Wherein X1 = I or 169-123-161- CDR3 DYFDY V, X2 = V or 124I; preferably, wherein X1 = I and X2 = V SEQ ID No: 134 IgHV4-34-01 VHGGSFSX1YX2 Wherein X1 = D or G 025-001-143- CDR1 and 019-021-027X2 = Y or F; preferably, wherein X1 = D and X2 = Y SEQ ID No: 135IgHV4-34-01 VH IX1HX2GSX3 Wherein X1 = H or N, 025-001-143- CDR2X2 = S or V, 019-021-027 and X3 = T or A; preferably, wherein X1 = H,X2 = S, and X3 = T SEQ ID No: 136 IgHV4-34-01 VH ARGX1X2X3SGWherein X1 = Y, N or L; 025-001-143- CDR3 X4YYFDX5 X2 = Y or I,019-021-027 X3 = D, G or A; X4 = V or Y; and X5 = Y or L; preferably,wherein X1 = Y, X2 = Y, X3 = D, X4 = V, and X5 = Y SEQ ID No: 137IgHV4-34-01 VH GGSFSX1YY Wherein X1 = G or D, 091-032-035- CDR1preferably G 036-054-094 SEQ ID No: 138 IgHV4-34-01 VH IX1HSGX2TWherein X1 = Y, 091-032-035- CDR2 N or H; and 036-054-094 X2 = D or S;preferably, wherein X1 = Y and X2 = D SEQ ID No: 139 IgHV4-34-01 VHARLX1X2GSGX Wherein X1 = Y, F or W; 091-032-035- CDR3 3YYX4DYX2 = F or Y; 036-054-094 X3 = I, T or S; and X4 = L or F;preferably, wherein X1 = Y, X2 = F, X3 = I, and X4 = L SEQ ID No: 140IgHV3-30-01 VH GFTFSX1X2A Wherein X1 = T or F, 129 CDR1X2 = F or Y; preferably, wherein X1 = T and X2 = F SEQ ID No: 141IgHV3-30-01 VH ISYDGX1X2K Wherein X1 = G or S, 129 CDR2 X2 = H or N;preferably, wherein X1 = G and X2 = H SEQ ID No: 142 IgHV3-30-01 VHARGLGVWGX1F Wherein X1 = A or Y, 129 CDR3 DY preferably A SEQ ID No: 143IgHV3-23-01 VH GFTFX1X2YX3 Wherein X1 = S, N or T; 098-105-100- CDR1X2 = N, D or S; 125-162 and X3 = G or A; preferably, wherein X1 = S,X2 = N and X3 = G SEQ ID No: 144 IgHV3-23-01 VH ISGX1X2X3X4TWherein X1 = S or T, 098-105-100- CDR2 X2 = A or G, 125-162 X3 = Y or G,X4 = S or A; preferably, wherein X1 = S, X2 = A, X3 = Y, X4 = SSEQ ID No: 145 IgHV3-23-01 VH AKX1X2X3X4G Wherein X1 = A or G;098-105-100- CDR3 SGSYYTX5FDY X2 = H or Y; X3 = Y or T; 125-162X4 = H, F or L; X5 = L or S; preferably, wherein X1 = A; X2 = H; X3 = Y;X4 = H;X5 = L SEQ ID No: 146 IgHV5-51-01 VH GYSFX1X2YWWherein X1 = S or T, 127 CDR1 X2 = I or S; preferably, wherein X1 = S,X2 = I SEQ ID No: 147 IgHV5-51-01 VH IX1PGDSDX2 Wherein X1 = F or Y, 127CDR2 X2 = I or T; preferably, wherein X1 = F, X2 = I SEQ ID No: 148IgHV5-51-01 VH ARQPGDWSPR 127 CDR3 HWYFDL SEQ ID No: 149 IgHV5-51-01 VHGYXFTSYW Wherein X = N or S, 159 CDR1 Preferably N SEQ ID No: 51IgHV5-51-01 VH IYPGDSDT 159 CDR2 SEQ ID No: 52 IgHV5-51-01 VHARWGTYYDILT 159 CDR3 GYFN SEQ ID No: 71 IgHV1-18-01 VH GYTFTSYG 132 CDR1SEQ ID No: 150 IgHV1-18-01 VH ISAYNGNX Wherein X = S or T, 132 CDR2Preferably S SEQ ID No: 151 IgHV1-18-01 VH AREYSYDSGTY 132 CDR3 FYYGMDVSEQ ID No: 152 IgHV3-30- VH GFTFSX1X2X3 Wherein X1 = D or S,153-033-160- 03-01 CDR1 X2 = Y or H, 166-152-167 X3 = V or A;preferably, wherein X1 = D, X2 = Y, X3 = V SEQ ID No: 153 IgHV3-30- VHISYDGSX1X2 Wherein X1 = N or Y, 153-033-160- 03-01 CDR2 X2 = K or E,166-152-167 preferably wherein X1 = N and X2 = K SEQ ID No: 154IgHV3-30- VH ARGX1X2X3X4 Wherein X1 = G, 153-033-160- 03-01 CDR3X5X6GX7FDY D or S; X2 = I 166-152-167 or Y; X3 = T or I; X4 = G or S;X5 = T or S; X6 = T or S; X7 = Y or V; preferably, whereinX1 = G; X2 = I; X3 = T; X4 = G; X5 = T; X6 = T; and X7 = V SEQ ID No: 13IgKV1-12-01 VL QGISSW 050-084-049- CDR1 051-055 050-084-049- IgKV1-12-01VL XAS Wherein X = A or V 051-055 CDR2 SEQ ID No: 155 IgKV1-12-01 VLQQANSFPXT Wherein X = I or L 050-084-049- CDR3 051-055 SEQ ID No: 6IgKV3-11-01 VL QSVSSY 169-124-161- CDR1 123 169-124-161- IgKV3-11-01 VLDXS Wherein X = A or T, 123 CDR2 preferably A SEQ ID No: 156 IgKV3-11-01VL QQRSXWPRT Wherein X = N or H, 169-124-161- CDR3 preferably 123 NSEQ ID No: 157 IgKV1D-16- VL QGISXW Wherein X = R or S, 025-001-019- 01CDR1 preferably 143-021-027 R 025-001-019- IgKV1D-16- VL AAS 143-021-02701 CDR2 SEQ ID No: 164 IgKV1D-16- VL QQYNSXPIT Wherein X = Y or F,025-001-019- 01 CDR3 preferably 143-021-027 Y SEQ ID No: 33 IgKV1D-16-VL QGISSW 091-032-035- 01 CDR1 036-054-094 091-032-035- IgKV1D-16- VLAX1X2 Wherein X1 = A or T, 036-054-094 01 CDR2 and X2 = S or F;preferably, wherein X1 = A and X2 = S SEQ ID No: 158 IgKV1D-16- VLQQYNSFPPT 091-032-035- 01 CDR3 036-054-094 SEQ ID No: 159 IgKV1D-16- VLQGIXSW Wherein X = S or N, 098-100-105- 01 CDR1 preferably 125-162 S098-100-105- IgKV1D-16- VL AAS 125-162 01 CDR2 SEQ ID No: 160 IgKV1D-16-VL QQYNSYPXT Wherein X = Y or L, 098-100-105- 01 CDR3 preferably 125-162Y SEQ ID No: 161 IgKV1D-16- VL QGIX1X2W Wherein X1 = S or N;153-152-166- 01 CDR1 X2 = S or 167-160-033 N; preferably, whereinX1 = X2 = S 153-152-166- IgKV1D-16- VL XAS Wherein X = D or A,167-160-033 01 CDR2 preferably D SEQ ID No: 162 IgKV1D-16- VL QQYXSYPITWherein X = K or N, 153-152-166- 01 CDR3 preferably 167-160-033 K

Example 11—Purification of Antibodies

Culture supernatant was filtered over 0.2 μm dead-end filters, loaded on5 ml MabSelect SuRe columns (GE Health Care) and eluted with 0.1 Msodium citrate-NaOH, pH 3. The eluate was immediately neutralized with2M Tris-HCl, pH 9 and dialyzed overnight to 12.6 mM NaH2PO4, 140 mMNaCl, pH 7.4 (B.Braun). Alternatively, subsequent to purification, theeluate was loaded on a HiPrep Desalting column and the antibody wasexchanged into 12.6 mM NaH2PO4, 140 mM NaCl, pH 7.4 (B.Braun) buffer.After dialysis or exchange of buffer, samples were sterile filtered over0.2 μm dead-end filters. Purity was determined by SDS-PAGE andconcentration was measured by nephelometry and absorbance at 280 nm.Purified antibodies were stored at 4° C. Mass spectrometry was performedto identify the molecular mass of the antibody heavy and light chainsexpressed by the hybridomas as described in Example 9.

Example 12—Binding of HER2 Clones to Tumor Cells ExpressingMembrane-Bound HER2 Measured by Means of FACS Analysis

The binding of HER2 antibodies to AU565 cells (purchased at ATCC,CRL-2351) and A431 cells (purchased at ATCC, CRL-1555), was tested usingflow cytometry (FACS Canto II, BD Biosciences). Qifi analysis (Dako,Glostrup, Denmark) revealed that AU565 cells expressed on average1,000,000 copies of HER2 protein per cell, whereas A431 cells expressedon average 15,000 copies per cell. Binding of HER2 antibodies wasdetected using a Phycoerythrin (PE)-conjugated goat-anti-human IgGantibody (Jackson). Trastuzumab (clinical-grade Herceptin®) was used aspositive control antibody, and an isotype control antibody was used asnegative control antibody. EC₅₀ values were determined by means ofnon-linear regression (sigmoidal dose-response with variable slope)using GraphPad Prism V4.03 software (GraphPad Software, San Diego,Calif., USA).

As shown in FIG. 3, all tested HER2 antibodies bound to HER2 expressedon both AU565 and A431 cells in a dose-dependent manner. The EC₅₀ valuesfor binding varied between 0.336-2.290 μg/mL for AU565 cells and0.068-1.135 μg/mL for A431 cells. Especially on A431 cells, largedifferences in EC₅₀ values were observed between the tested antibodies.However, antibody 098 had the best (i.e., lowest) EC₅₀ value on bothtypes of cells. Also some differences in maximum binding levels wereobserved between different antibodies, on both AU565 and A431 cells. Ofthe tested antibodies, antibody 098 also had the highest maximum bindinglevel on AU565 cells, whereas antibody 025 had the highest maximumbinding level on A431 cells.

Example 13—Binding of HER2 Antibodies to Membrane-Bound HER2 Expressedon Rhesus Epithelial Cells Measured by Means of FACS Analysis

To determine cross-reactivity with Rhesus HER2, the binding of HER2antibodies to HER2-positive Rhesus epithelial cells (4MBr-5 purchased atATCC) was tested using flow cytometry (FACS Canto II, BD Biosciences). APhycoerythrin-conjugated goat-anti-human IgG antibody (Jackson) was usedas a secondary conjugate. An isotype control antibody was used asnegative control antibody.

As shown in FIG. 4, all tested HER2 antibodies were cross-reactive withRhesus monkey HER2. At both tested concentrations (1 μg/mL and 10μg/mL), the HER2 antibodies were able to bind specifically to Rhesusmonkey HER2. Antibody 127 demonstrated poor binding at 1 μg/mLconcentration, but showed good binding at 10 μg/mL concentration.Antibody 098 had the highest binding level at both antibodyconcentrations. No binding was observed with the isotype controlantibody.

Example 14—Competition of HER2 Antibodies for Binding to SolubleHer2ECDHis Measured in Sandwich-ELISA

The optimal coating concentrations of the tested HER2 antibodies andoptimal Her2ECDHis concentration were determined in the followingmanner: ELISA wells were coated overnight at 4° C. with HER2 HuMabsserially diluted in PBS (0.125-8 μg/mL in 2-fold dilutions). Next, theELISA wells were washed with PBST (PBS supplemented with 0.05% Tween-20[Sigma-Aldrich, Zwijndrecht, The Netherlands]) and blocked for one hourat room temperature (RT) with PBSTC (PBST supplemented 2% [v/v] chickenserum [Gibco, Paisley, Scotland]). The ELISA wells were then washed withPBST and incubated for one hour at RT with Her2ECDHis serially dilutedin PBSTC (0.25-2 μg/mL in 2-fold dilutions). Unbound Her2ECDHis waswashed away with PBST, and bound Her2ECDHis was incubated for one hourat RT with 0.25 μg/mL biotinylated rabbit-anti-6×his-biot (Abcam,Cambridge, UK). The plate was thereafter washed with PBST and incubatedfor one hour with 0.1 μg/mL Streptavidin-poly-HRP (Sanquin, Amsterdam,The Netherlands) diluted in PBST. After washing, the reaction wasvisualized through a 15 minutes incubation with 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS: one ABTS tablet dilutedin 50 mL ABTS buffer (Roche Diagnostics, Almere, The Netherlands)) at RTprotected from light. The colorization was stopped by adding an equalvolume of oxalic acid (Sigma-Aldrich, Zwijndrecht, The Netherlands).Fluorescence at 405 nm was measured on a microtiter plate reader (BiotekInstruments, Winooski, USA). The antibody concentrations that resultedin sub-optimal binding of each antibody were determined and used for thefollowing cross-block experiments.

Each HER2 antibody was coated to the ELISA wells at the sub-optimal dosethat was determined as described above. After blocking of the ELISAwells, the wells were incubated with the predetermined concentration of1 μg/mL biotinylated Her2ECDHis in the presence or absence of an excessof a second (competitor) HER2 antibody. The ELISA was then performed asdescribed above. Residual binding of Her2ECDHis to the coated antibodywas expressed as a percentage relative to the binding observed in theabsence of competitor antibody. Percentage competition was thendetermined as 100 minus the percentage of inhibition. 75% competitionwas considered as complete cross-block, whereas 25-74% competition wasconsidered as partial cross-block, and 0-24% competition was considerednon-blocking.

As shown in Table 5, all HER2 antibodies were found to be able to blockbinding to Her2ECDHis, at least partially, for themselves. Afterdividing the antibodies into 3 major cross-block groups, all antibodieswere tested for competition with at least one representative antibodyfrom each group.

The first group comprised trastuzumab and antibodies 169, 050 and 084,which blocked each other for binding to Her2ECDHis, but did notcross-block antibodies from other groups.

The second group comprised pertuzumab and antibodies 025, 091 and 129,which blocked each other for binding to Her2ECDHis, except forantibodies 129 and 091 which both cross-blocked pertuzumab and 025, butnot each other. None of the antibodies of group 2 blocked antibodiesfrom other groups.

A third group comprised antibodies C1, F5, 127, 098, 132, 153 and 159,which did not cross-block any antibody from the other groups. Withinthis group 3, some variation was observed. Antibody 127 was the onlyantibody that was able to cross-block all other antibodies in this groupfor binding to Her2ECDHis; antibody 159 cross-blocked all otherantibodies within this group, except 132; clone 098 cross-blocked allantibodies of group 3, except 132 and 153; antibody 153 cross-blocked127, 132 and 159 for binding to Her2ECDHis, but not 098, C1 or F5; clone132 cross-blocked 127, 132 and 153. When added as competitor antibodies,F5 and C1 only demonstrated cross-blocking of each other. However, thereverse reaction also revealed competition with antibodies 127, 098 and159, but not 153 and 132. Possibly, these differences may have resultedfrom lower affinities of antibodies C1 and F5 for Her2ECDHis.

Values higher than 100% can be explained by avidity effects and theformation of antibody-Her2ECDHis complexes containing two non-competingantibodies.

TABLE 5 Competition and cross-blocking of HER2 antibodies for binding toHer2ECDHis Immobilized Competing mAb → mAb ↓ tras 169 050 084 pert 025091 129 C1 F5 127 159 098 153 132 Trastuzumab 6 15 6 51 100 107 100 85103 99 115 90 101 101 101 TH1014-169 19 45 21 73 101 98 105 106 ND ND NDND 105 102 ND TH1014-050 13 30 12 74 95 104 98 110 ND ND ND ND 102 104ND TH1014-084 74 73 76 20 101 106 104 104 ND ND ND ND 109 98 NDTH1014-pert 104 100 94 95 9 20 19 39 106 125 116 81 103 100 109TH1014-025 98 98 100 104 8 18 21 15 ND ND ND ND 102 99 ND TH1014-091 9999 95 100 5 13 15 78 ND ND ND ND 98 98 ND TH1014-129 93 99 97 92 22 5576 12 ND ND ND ND 106 98 ND TH1014-C1 89 ND ND ND ND ND ND ND 65 58 7353 58 77 90 TH1014-F5 197 ND ND ND ND ND ND ND 70 21 62 15 16 80 125TH1014-127 102 ND ND ND ND ND ND ND 112 88 11 8 58 21 44 TH1014-159 111ND ND ND 112 ND ND ND 96 86 15 6 11 40 79 TH1014-098 107 102 100 103 104108 104 107 125 96 21 9 17 110 142 TH1014-153 134 111 103 107 121 97 102106 257 96 27 23 115 28 33 TH1014-132 353 ND ND ND 288 ND ND ND 422 37930 131 309 41 32 Cross-block 1 1 1 1 2 2 2 2b 3a 3a 3a 3a 3a 3b 3b group

Depicted values are mean percentages of binding relative to the bindingobserved in the absence of competitor antibody, of two independentexperiments. Competition experiments with HEK produced TH1014-C1 andTH1014-F5 were performed once. Trastuzumab (clinical grade Herceptin©)and HEK-produced pertuzumab (TH1014-pert) were also tested.

Example 15—Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC)

SK-BR-3 cells (purchased at ATCC, HTB-30) were harvested (5×10⁶ cells),washed (twice in PBS, 1500 rpm, 5 min) and collected in 1 mL RPMI 1640medium supplemented with 10% cosmic calf serum (CCS) (HyClone, Logan,Utah, USA), to which 200 μCi ⁵¹Cr (Chromium-51; Amersham BiosciencesEurope GmbH, Roosendaal, The Netherlands) was added. The mixture wasincubated in a shaking water bath for 1.5 hours at 37° C. After washingof the cells (twice in PBS, 1500 rpm, 5 min), the cells were resuspendedin RPMI 1640 medium supplemented with 10% CCS, counted by trypan blueexclusion and diluted to a concentration of 1×10⁵ cells/mL.

Meanwhile, peripheral blood mononuclear cells (PBMCs) were isolated fromfresh buffy coats (Sanquin, Amsterdam, The Netherlands) using standardFicoll density centrifugation according to the manufacturer'sinstructions (lymphocyte separation medium; Lonza, Verviers, France).After resuspension of cells in RPMI 1640 medium supplemented with 10%CCS, cells were counted by trypan blue exclusion and concentrated to1×10⁷ cells/mL.

Trastuzumab was produced in CHO cells resulting in an (increased)non-core fucosylation grade of 12.4%, whereas the other HER2 antibodieswere produced in HEK cells, resulting on average in 4% non-corefucosylation.

For the ADCC experiment, 50 μL ⁵¹Cr-labeled SK-BR-3 cells (5.000 cells)were pre-incubated with 15 μg/mL HER2 antibody (IgG1,κ) in a totalvolume of 100 μL RPMI medium supplemented with 10% CCS in a 96-wellmicrotiter plate. After 15 min at RT, 50 μL PBMCs (500,000 cells) wereadded, resulting in an effector to target ratio of 100:1. The maximumamount of cell lysis was determined by incubating 50 μL ⁵¹Cr-labeledSK-BR-3 cells (5000 cells) with 100 μL 5% Triton-X100. The amount ofspontaneous lysis was determined by incubating 5000 ⁵¹Cr-labeled SK-BR-3cells in 150 μL medium, without any antibody or effector cells. Thelevel of antibody-independent cell lysis was determined by incubating5000 SK-BR-3 cells with 500,000 PBMCs without antibody. Subsequently,the cells were incubated 4 hr at 37° C., 5% CO₂. To determine the amountof cell lysis, the cells were centrifuged (1200 rpm, 3 min) and 75 μL ofsupernatant was transferred to micronic tubes, after which the released⁵¹Cr was counted using a gamma counter. The measured counts per minute(cpm) were used to calculate the percentage of antibody-mediated lysisas follows:

(cpm sample−cpm Ab-independent lysis)/(cpm max. lysis−cpm spontaneouslysis)×100%

As shown in FIG. 5, HER2 antibodies from cross-block groups 1 and 2induced efficient lysis of SK-BR-3 cells through ADCC. From group 3,antibody 153 was the only antibody that induced efficient ADCC, antibody132 induced about 10% ADCC, and clones 098, 159 and 127 did not induceADCC.

Example 16—Inhibition of Ligand-Independent Proliferation of AU565 Cells

HER2 antibodies were tested for their ability to inhibit proliferationof AU565 cells in vitro. Due to the high HER2 expression levels on AU565cells (˜1,000,000 copies per cell as described in Example 12), HER2 isconstitutively active in these cells and thus not dependent onligand-induced heterodimerization.

In a 96-well tissue culture plate (Greiner bio-one, Frickenhausen,Germany), 9000 AU565 cells were seeded per well in the presence of 10μg/mL HER2 antibody in serum-free cell culture medium. As a control,cells were seeded in serum-free medium without antibody. After 3 days,the amount of viable cells was quantified with Alamarblue (BioSourceInternational, San Francisco, US) according to the manufacturer'sinstructions. Fluorescence was monitored using the EnVision 2101Multilabel reader (PerkinElmer, Turku, Finland) with standard Alamarbluesettings. The Alamarblue signal of antibody-treated cells was plotted asa percentage relative to untreated cells. Dunnett's test was applied forstatistical analysis.

The results are shown in FIG. 6, depicting the percentage proliferationof AU565 cells after HER2 antibody treatment compared to untreatedcells, which was set to 100%. Of the tested Group 1 antibodies,trastuzumab, 050 and 169 demonstrated significant inhibition of AU565cell proliferation (P<0.05), whereas 084 had no effect. None of thetested antibodies from group 2 (Pertuzumab, 025, 092 and 129) was ableto inhibit AU565 cell proliferation. The tested antibodies from group 3(098 and 153) did not inhibit AU565 proliferation. In contrast, bothantibodies induced enhanced proliferation of AU565 cells compared tountreated cells (098 more than 153). Enhancing proliferation can be anadvantage in some therapeutic applications of ADC-conjugates, e.g.,where the cytotoxic action of the drug relies on, or is enhanced by,cell proliferation. For trastuzumab and pertuzumab, this was inaccordance with the results described by Juntilla et al. (Cancer Cell2009; 15(5):353-355).

Example 17—Inhibition of Ligand-Induced Proliferation of MCF-7 Cells

Since HER2 is an orphan receptor, its signaling is mainly dependent onactivation of other ErbB-family members such as EGFR and Her3. Uponligand binding, these two receptors can bind to and activate the HER2receptor, resulting in e.g. proliferation. Various publications describethat pertuzumab efficiently inhibits Heregulin-01-induced proliferation(Franklin M C. Cancer Cell 2004/Landgraf R. BCR 2007). For trastuzumab,it has been described that it has little effect on Heregulin-β1-inducedHER2/HER3 heterodimerization and proliferation (Larsen S S., et al.,Breast Cancer Res Treat 2000; 58:41-56; Agus D B., et al., Cancer Cell2002; 2:127-137; Wehrman et al. (2006), supra).

To investigate the ability of the present human HER2 antibodies tointerfere with Heregulin-01-induced HER2/HER3 heterodimers, aHeregulin-01-induced proliferation assay was performed. Therefore, MCF7cells (purchased at ATCC, HTB-22) expressing ˜20.000 HER2 molecules percell, were seeded in a 96-wells tissue culture plate (Greiner bio-one)(2.500 cells/well) in complete cell culture medium. After 4 hours, thecell culture medium was replaced with starvation medium containing 1%Cosmic Calf Serum (CCS) and 10 μg/mL HER2 antibody. Next, Heregulin-01(PeproTech, Princeton Business Park, US) diluted in 1% CCS containingstarvation medium was added to the wells to a final concentration of 1.5ng/ml. After 4 days incubation, the amount of viable cells wasquantified with Alamarblue (BioSource International) according to themanufacturer's instructions.

Fluorescence was monitored using the EnVision 2101 Multilabel reader(PerkinElmer) with standard Alamarblue settings. The Alamarblue signalof HER2 antibody-treated ligand-induced cells was plotted as apercentage signal compared to ligand-induced cells incubated withoutHER2 antibody. Dunnett's test was applied for statistical analysis.

FIG. 7 shows the percentage of viable MCF7 cells stimulated withHeregulin-01 and treated with the indicated HER2 antibody, relative tothe viable cells after stimulation with Heregulin-01 in the absence ofHER2 antibody, which was set to 100%. MCF-7 proliferation in absence ofboth Heregulin-01 and antibody was also depicted (none). Antibodies 025,091, 129, 153 and pertuzumab (TH1014-pert) demonstrated significantinhibition of Heregulin-01-induced MCF-7 proliferation (P<0.05). Alsotrastuzumab showed some inhibition of Heregulin-01-induced proliferationof MCF-7 cells, although not as efficient as the other tested HER2antibodies. It has been reported that domain IV of HER2 is involved inthe stabilization of EGFR/HER2 heterodimers, but without details on itscontribution to HER2/HER3 heterodimers (Wehrman et al., supra).Antibodies 050, 084, 169 and 098 had no statistically significant effecton Heregulin-01-induced proliferation of MCF-7 cells. Without beinglimited to theory, this suggests that these antibodies do not inhibitligand-induced HER2/HER3 heterodimerization.

Example 18—Anti-Kappa-ETA′ Assay

To investigate the suitability of HER2 antibodies for an antibody-drugconjugate approach, a generic in vitro cell-based killing assay usingkappa-directed pseudomonas-exotoxin A (anti-kappa-ETA′) was developed.The assay makes use of a high affinity anti-kappa domain antibodyconjugated to a truncated form of the pseudomonas-exotoxin A. Uponinternalization, the anti-kappa-ETA′ domain antibody undergoesproteolysis and disulfide-bond reduction, separating the catalytic fromthe binding domain. The catalytic domain is transported from the Golgito the endoplasmic reticulum via the KDEL retention motif, andsubsequently translocated to the cytosol where it inhibits proteinsynthesis and induces apoptosis (ref. Kreitman R J. BioDrugs 2009;23(1):1-13). In this assay, to identify HER2 antibodies that enableinternalization and killing through the toxin, HER2 antibodies arepreconjugated with the anti-kappa-ETA′ before incubation withHER2-positive cells.

First, the optimal concentration of anti-kappa-ETA′ was determined foreach cell line, i.e. the maximally tolerated dose that does not lead toinduction of non-specific cell death. AU565 cells (7500 cells/well) andA431 cells (2500 cells/well) were seeded in normal cell culture mediumin 96-wells tissue culture plate (Greiner bio-one) and allowed to adherefor at least 4 hours. Next, cells were incubated with 100, 10, 1, 0.1,0.01, 0.001 and 0 μg/mL anti-kappa-ETA′ dilutions in normal cell culturemedium. After 3 days, the amount of viable cells was quantified withAlamarblue (BioSource International, San Francisco, US) according to themanufacturer's instruction. Fluorescence was monitored using theEnVision 2101 Multilabel reader (PerkinElmer, Turku, Finland) withstandard Alamarblue settings. The highest concentration anti-kappa-ETA′that did not kill the cells by itself was used for following experiments(0.5 μg/mL for AU565 and 1 μg/mL for A431).

Next, antibody-mediated internalization and killing by the toxin wastested for different HER2 antibodies. Cells were seeded as describedabove. Dilution-series of HER2 antibodies were pre-incubated for 30minutes with the predetermined concentration anti-kappa-ETA′ beforeadding them to the cells. After 3 days of incubation, the amount ofviable cells was quantified as described above. The Alamarblue signal ofcells treated with anti-kappa-ETA′ conjugated antibodies was plottedcompared to cells treated with antibody alone. 23.4 μg/mL Staurosporinwas used as positive control for cell killing. An isotype controlantibody was used as negative control.

As shown in FIG. 8A,B and Table 6, all anti-kappa-ETA′-conjugated HER2antibodies were able to kill AU565 cells in a dose-dependent manner. Alltested anti-kappa-ETA′-conjugated HER2 antibodies demonstrated betterkilling of AU565 cells compared to both anti-kappa-ETA′-conjugatedtrastuzumab and anti-kappa-ETA′-conjugated pertuzumab (TH1014-pert).Moreover, the percentage of killed AU565 cells was higher foranti-kappa-ETA′-conjugated HER2 antibodies (70.3-49.9%), compared toanti-kappa-ETA′-conjugated trastuzumab (31.9%) andanti-kappa-ETA′-conjugated pertuzumab (47.51%), and the EC₅₀ values wereincreased. EC₅₀ values for anti-kappa-ETA′-conjugated HER2 antibodiesranged between 12.12 ng/mL and 46.49 ng/mL) compared to 78.49 ng/mL foranti-kappa-ETA′-conjugated trastuzumab and 117.8 ng/mL foranti-kappa-ETA′-conjugated pertuzumab. Antibody 159 had the highestpercentage of cell-kill, and 098 the lowest EC₅₀.

TABLE 6 Data shown are EC₅₀ values and maximal percentage cell kill ofAU565 cells treated with anti-kappa-ETA′ -conjugated HER2 antibodies,measured in one representative experiment. Cell-kill induced byStaurosporin was set as 100% and MFI of untreated cells was set as 0%.Ndet = not detected. % cells EC50 antibody killed ng/mL PC1014-159 70.334.93 PC1014-127 69.0 34.46 PC1014-132 61.6 39.35 PC1014-129 60.8 30.85PC1014-153 60.3 32.26 PC1014-025 60.0 16.71 PC1014-098 58.7 12.12PC1014-084 58.1 26.97 PC1014-050 52.4 12.71 PC1014-091 50.6 46.49PC1014-169 49.9 35.62 TH1014-pert 47.5 117.8 trastuzumab 31.9 78.49isotype control Ndet Ndet

As shown in FIG. 8C,D and Table 7, antibodies 025, 091, 098, 129 and 153were able to induce effective killing of A431 cells (≥75%). The highestpercentage of cell-kill, and lowest EC₅₀ was shown by antibody 098. Whenconjugated to anti-kappa-ETA′, trastuzumab and isotype control antibodydid not induce killing of A431 cells. Antibodies 169, 084 and pertuzumabinduced percentages of cell kill of no more than about 50%. No cell killwas observed with non-conjugated HER2 antibodies.

TABLE 7 Data shown are EC₅₀ values and maximal percentage cell kill ofA431 cells treated with anti-kappa-ETA′- conjugated HER2 antibodies,measured in one representative experiment. Cell kill induced byStaurosporin was setas 100% and MFI of untreated cells was set as 0%.“NDet” means not detected. % cells EC50 antibody killed ng/mL PC1014-02586.7  ~9.77 PC1014-084 50.5 ND PC1014-091 83.3  ~9.86 PC1014-098 87.2 1.65 PC1014-129 75.9 ~10.60 PC1014-153 82.4 ~10.11 PC1014-169 34.0 NDTH1014-pert 37.0  61.58 trastuzumab Ndet Ndet isotype control NDet NDet

Example 19—Internalization of HER2 Antibodies Measured with anFMAT-Based Fab-CypHer5E Assay

To investigate whether the enhanced killing of AU565 cells observed inthe kappa-toxin-ETA′ assay described in the previous Example correlatedwith enhanced internalization of HER2 antibodies, a fab-CypHer5E-basedinternalization assay was performed. CypHer5E is a pH sensitive dyewhich is non-fluorescent at basic pH (extracellular: culture medium) andfluorescent at acidic pH (intracellular: lysosomes), with an aciddissociation constant (pKa) of 7.3.

AU565 cells were seeded in 384-well tissue culture plates (Greinerbio-one), at a density of 3000 cells/well in normal cell culture mediumsupplemented with 240 ng/mL fab-CypHer5E (conjugation ofGoat-fab-anti-Human IgG [Jackson] with CypHer5E [GE Healthcare,Eindhoven, The Netherlands] was made according to manufacturer'sinstructions). Next, HER2 antibodies were serially diluted in normalcell culture medium, added to the cells and left at room temperature for9 hours. Mean fluorescent intensities (MFI) of intracellular CypHer5Ewere measured using the 8200 FMAT (Applied Biosystems, Nieuwerkerk A/DIJssel, The Netherlands) and ‘counts×fluorescence’ was used as read-out.An isotype control antibody was used as negative control antibody. EC₅₀values and maximal MFI were determined by means of non-linear regression(sigmoidal dose-response with variable slope) using GraphPad Prism V4.03software (GraphPad Software, San Diego, Calif., USA).

The results are shown in Table 8, depicting the EC₅₀ and maximal MFIvalues for all tested HER2 antibodies in the CypHer5E internalizationassay with AU565 cells. The maximal MFI values indicate how many HER2receptors are internalized upon antibody binding. All HER2 antibodiesshowed higher maximal MFI values (137,904-38,801) compared totrastuzumab (35,000) and pertuzumab (TH1014-pert) (32,366), indicatingthat the tested HER2 antibodies induced enhanced receptorinternalization. Notably, antibodies that did not compete withtrastuzumab or TH1014-pert induced more receptor internalizationcompared to antibodies that did compete with trastuzumab andTH1014-pert, with the highest MFI achieved by antibodies 098 and 127.Without being limited to theory, this might be inherent to an inabilityto inhibit HER2 heterodimerization.

TABLE 8 Cypher-5-based internalization assay of HER2 antibodies. Datashown are MFI and EC₅₀ values of one representative experiment of twoexperiments with AU565 cells treated with fab-CypHer5E-labeled HER2antibodies. Some EC₅₀ values could not be calculated (ND). Cypher 5Antibody EC₅₀ ng/mL Maximal MFI PC1014-025  30.05 63428 PC1014-091 32.99 50711 mAbs that compete PC1014-129  7.15 60302 {close oversizebracket} with Herceptin TH1014-pert 530 32366 PC1014-169 ND 38801 mAbsthat compete PC1014-084  30.51 71059 {close oversize bracket} withTH1014-pert trastuzumab  21.70 35000 PC1014-098  13.77 134575 PC1014-127 ~9.68 137904 mAbs that compete PC1014-159 ND 92427 {close oversizebracket} wtih TH1014-F5 TH1014-F5  22.65 113116 PC1014-132  11.42 112270{close oversize bracket} Non-competing mAbs PC1014-153 ~14.91 87531

Example 20: Generation of Bispecific Antibodies by 2-MEA-Induced Fab-ArmExchange

An in vitro method for producing bispecific antibodies is described inWO 2008119353 (Genmab) and reported van der Neut-Kolfschoten et al.(Science. 2007 Sep. 14; 317(5844):1554-7). Herein, a bispecific antibodyis formed by “Fab-arm” or “half-molecule” exchange (swapping of a heavychain and attached light chain) between two monospecific IgG4- orIgG4-like antibodies upon incubation under mildly reducing conditions.This Fab-arm exchange reaction is the result of a disulfide-bondisomerization reaction wherein the inter heavy-chain disulfide bonds inthe hinge regions of monospecific antibodies are reduced and theresulting free cysteines form a new inter heavy-chain disulfide bondwith cysteine residues of another antibody molecule with a differentspecificity. The resulting product is a bispecific antibody having twoFab arms with different sequences.

In a novel invention the knowledge of this natural IgG4 Fab-arm exchangeis adapted to generate a method to produce stable IgG1-based bispecificantibodies. The bispecific antibody product generated by this methoddescribed below will no longer participate in IgG4 Fab-arm exchange. Thebasis for this method is the use of complimentary CH3 domains, whichpromote the formation of heterodimers under specific assay conditions.To enable the production of bispecific antibodies by this method, IgG1molecules carrying certain mutations in the CH3 domain were generated:in one of the parental IgG1 antibody T350I, K370T and F405L mutations inthe other parental IgG1 antibody the K409R mutation.

To generate bispecific antibodies, these two parental antibodies, eachantibody at a final concentration of 0.5 mg/mL (equimolarconcentration), were incubated with 25 mM 2-mercaptoethylamine-HCl(2-MEA) in a total volume of 100 μL TE at 37° C. for 90 min. Thereduction reaction is stopped when the reducing agent 2-MEA is removedby using spin columns (Microcon centrifugal filters, 30 k, Millipore)according to the manufacturer's protocol.

Example 21—HER2×HER2 Bispecific Antibodies Tested in an In VitroKappa-Directed ETA′ Killing Assay

The example shows that HER2×HER2 bispecific antibodies can deliver acytotoxic agent into tumor cells after internalization in a generic invitro cell-based killing assay using kappa-directed pseudomonas-exotoxinA (anti-kappa-ETA′). This assay makes use of a high affinity anti-kappadomain antibody conjugated to a truncated form of thepseudomonas-exotoxin A. Similar fusion proteins of antibody bindingproteins (IgG-binding motif from Streptococcal protein A or protein G)and diphtheria toxin or Pseudomonas exotoxin A have previously been(Mazor Y. et al., J. Immunol. Methods 2007; 321:41-59); Kuo S R. et al.,2009 Bioconjugate Chem. 2009; 20:1975-1982). These molecules in contrastto anti-kappa-ETA′ bound the Fc part of complete antibodies. Uponinternalization and endocytic sorting the anti-kappa-ETA′ domainantibody undergoes proteolysis and disulfide-bond reduction, separatingthe catalytic from the binding domain. The catalytic domain is thentransported from the Golgi to the endoplasmic reticulum via a KDELretention motif, and subsequently translocated to the cytosol where itinhibits protein synthesis and induces apoptosis (Kreitman R J. et. al.,BioDrugs 2009; 23:1-13).

The anti-HER2 antibodies used in this example are 025, 153 and 169. Inaddition a fully human monoclonal IgG1,κ antibody 005 of the followingsequence was used:

005: SEQ ID VH 005 EVQLVQSGAEVKKPGESLKI NO: 164 SCKASGYSFHFYWIGWVRQMPGKGLEWMGSIYPGDSDTRY RPSFQGQVTISADKSISTAY LQWTSLKASDTAIYYCARQRGDYYYFYGMDVWGQGTTVTV SS SEQ ID VL 005 EIVLTQSPGTLSLSPGERAT NO: 165LSCRASQSVSSSYLAWYQQK PGQVPRLLIYGASSRATGIP DRFSGSGSGTDFTLTISRLEPEDFAVYYCQQYGSSLTFGG GTKVEIK SEQ ID VH GYSFHFYW NO: 166 CDR1 SEQ ID VHYPGDSDT NO: 167 CDR2 SEQ ID VH ARQRGDYYYFYGMDV NO: 168 CDR3 SEQ ID VLQSVSSSY NO: 169 CDR1 VL GAS CDR2 SEQ ID VL QQYGSSLT NO: 170 CDR3

The following antibodies were used as starting materials:

IgG1-005-ITL=005 IgG1,κ having Ile at position 350, Thr at position 370,and Leu at position 405IgG1-005-K409R=005 IgG1,κ having an Arg at position 409IgG1-025-ITL=025 IgG1,κ having Ile at position 350, Thr at position 370,and Leu at position 405IgG1-153-ITL=153 IgG1,κ having contains Ile at position 350, Thr atposition 370, and Leu at position 405IgG1-153-K409R=153 IgG1,κ having an Arg at position 409IgG1-169-K409R=169 IgG1,κ having an Arg at position 409

The following bispecific antibodies were generated in analogy with thebelow procedure:

IgG1-005-ITL×IgG1-169-K409R IgG1-025-ITL×IgG1-005-K409RIgG1-025-ITL×IgG1-153-K409R IgG1-025-ITL×IgG1-169-K409RIgG1-153-ITL×IgG1-005-K409R IgG1-153-ITL×IgG1-169-K409R

The bispecific antibodies were produced according to the proceduredescribed in example 20.

The antibody mixtures, containing each antibody at a final concentrationof 0.5 mg/mL, was incubated with 25 mM 2-mercaptoethylamine HCl (2-MEA)in a total volume of 100 μL TE at 37° C. for 90 min. To stop thereduction reaction, the reducing agent 2-MEA was removed by desaltingthe samples using spin columns (Microcon centrifugal filters, 30 k,Millipore) according to the manufacturer's recommendations.

The HER2×HER2 bispecific antibodies were pre-incubated with theanti-kappa-ETA′ before incubation with A431 cells. A431 cells express˜15,000 HER2 antibodies per cell (determined via Qifi analysis) and arenot sensitive to treatment with ‘naked’ HER2-antibodies.

First, the optimal concentration of anti-kappa-ETA′ was determined foreach cell line, i.e. the maximally tolerated dose that does not lead toinduction of non-specific cell death. A431 cells (2500 cells/well) wereseeded in normal cell culture medium in a 96-wells tissue culture plate(Greiner bio-one) and allowed to adhere for at least 4 hours. Thesecells were incubated with an anti-kappa-ETA′ dilution series, 100, 10,1, 0.1, 0.01, 0.001 and 0 μg/mL in normal cell culture medium. After 3days, the amount of viable cells was quantified with Alamarblue(BioSource International, San Francisco, US) according to themanufacturer's instruction. Fluorescence was monitored using theEnVision 2101 Multilabel reader (PerkinElmer, Turku, Finland) withstandard Alamarblue settings. The highest concentration anti-kappa-ETA′that did not kill the cells by itself (1 μg/mL for A431 cells) was usedfor following experiments.

Next, the effect of HER2×HER2 bispecific antibodies and HER2monospecific antibodies pre-incubated with anti-kappa-ETA′ was testedfor their ability to induce cell kill. A431 cells were seeded asdescribed above. A dilution series of the HER2 specific antibodies(monospecific and bispecific antibodies) was made and pre-incubated for30 min with the predetermined concentration of anti-kappa-ETA′ beforeadding them to the cells. After 3 days incubation at 37° C., the amountof viable cells was quantified as described above. The Alamarblue signalof cells treated with anti-kappa-ETA′ pre-incubated with the antibodieswas plotted compared to cells treated without antibody treatment. EC₅₀values and maximal cell death were calculated using GraphPad Prism 5software. Staurosporin (23.4 μg/mL) was used as positive control forcell killing. An isotype control antibody (IgG1/kappa; IgG1-3G8-QITL)was used as negative control.

FIG. 9 and table 9 shows that all anti-kappa-ETA′ pre-incubated HER2bispecific antibodies were able to kill A431 cells in a dose-dependentmanner. These results demonstrate that most HER2 bispecific antibodiestested were more effective than the monospecific antibody present in thecombination in this anti-kappa-ETA′ assay. In addition, the efficacy ofbispecific antibody 005X169, 025X169 and 153X169 showed that theefficacy of a monospecific antibody which lacks activity in this invitro kappa-directed ETA′ killing, HER2 specific antibody (169), can beincreased through bispecific combination with another HER2 specificantibody.

TABLE 9 EC₅₀ values and maximal percentage cell kill of AU565 cellstreated with anti-kappa-ETA′-conjugated HER2 × HER2 bispecificantibodies. “Ndet” means not detected. percentage EC50 antibody kill[ng/mL] Herceptin 2.79 Ndet IgG1-005-ITL 79.34 2.57 IgG1-005-K409R 79.832.87 IgG1-025-ITL 69.81 3.76 IgG1-153-ITL 70.66 12.45 IgG1-153-K409R72.84 15.47 IgG1-169-K409R 16.45 3.45 IgG1-005-ITL × IgG1-169-K409R59.94 4.28 IgG1-025-ITL × IgG1-005-K409R 63.45 4.27 IgG1-025-ITL ×IgG1-153-K409R 80.82 7.66 IgG1-025-ITL × IgG1-169-K409R 45.88 7.97IgG1-153-ITL × IgG1-005-K409R 80.05 4.51 IgG1-153-ITL × IgG1-169-K409R84.68 29.14

Example 22—HER2 Receptor Downmodulation by Incubation with BispecificAntibodies Targeting Different HER2 Epitopes

HER2×HER2 bispecific antibodies may bind two different epitopes on twospatially different HER2 receptors. This may allow other HER2×HER2bispecific antibodies to bind to the remaining epitopes on thesereceptors. This could result in multivalent receptor cross-linking(compared to dimerization induced by monovalent antibodies) andconsequently enhance receptor downmodulation. To investigate whetherHER2×HER2 bispecific antibodies induce enhanced downmodulation of HER2,AU565 cells were incubated with antibodies and bispecific antibodies forthree days. Total levels of HER2 and levels of antibody bound HER2 weredetermined.

AU565 cells were seeded in a 24-well tissue culture plate (100.000cells/well) in normal cell culture medium and cultured for three days at37° C. in the presence of 10 μg/mL HER2 antibody with either the ITL orthe K409R mutation or HER2×HER2 bispecific antibodies. As a control, thecombination of two monospecific HER2 antibodies, with unmodified IgG1backbones, was also tested (1:1), at a final concentration of 10 μg/mL.After washing with PBS, cells were lysed by incubating them for 30 minat room temperature with 25 μL Surefire Lysis buffer (Perkin Elmer,Turku, Finland). Total protein levels were quantified usingbicinchoninic acid (BCA) protein assay reagent (Pierce) followingmanufacturer's protocol. HER2 protein levels in the lysates wereanalyzed using a HER2-specific sandwich ELISA. Rabbit-anti-human HER2intracellular domain antibody (Cell Signaling) was used to capture HER2and biotinylated goat-anti-human HER2 polyclonal antibody R&D systems,Minneapolis, USA), followed by streptavidin-poly-HRP, were used todetect bound HER2. The reaction was visualized using 2,2′-azino-bis3-ethylbenzothiazoline-6-sulfonic acid (one ABTS tablet diluted in 50 mLABTS buffer [Roche Diagnostics, Almere, The Netherlands]) and stoppedwith oxalic acid (Sigma-Aldrich, Zwijndrecht, The Netherlands).Fluorescence at 405 nm was measured on a microtiter plate reader (BiotekInstruments, Winooski, USA) and the amount of HER2 was expressed as apercentage relative to untreated cells.

The results are shown in FIG. 10 and Table 10 which demonstrates thatall the tested HER2×HER2 bispecific antibodies induced ≥40% HER2downmodulation. Interestingly, all HER2×HER2 bispecific antibodiesdemonstrated increased HER2 downmodulation compared to both of theirmonospecific counterparts.

TABLE 10 HER2 × HER2 bispecific induced downmodulation of HER2 depictedas percentage HER2 compared to untreated cells % HER2 compared toantibody untreated cells Herceptin 71 IgG1-005-ITL 54 IgG1-005-K409R 50IgG1-025-ITL 64 IgG1-153-ITL 43 IgG1-153-K409R 40 IgG1-169-K409R 64IgG1-005-ITL × IgG1-169-K409R 29 IgG1-025-ITL × IgG1-005-K409R 38IgG1-025-ITL × IgG1-153-K409R 29 IgG1-025-ITL × IgG1-169-K409R 34IgG1-153-ITL × IgG1-005-K409R 23 IgG1-153-ITL × IgG1-169-K409R 28IgG1-005 + IgG1-169 28 IgG1-025 + IgG1-005 28 IgG1-025 + IgG1-153 23IgG1-025 + IgG1-169 25 IgG1-153 + IgG1-005 23 IgG1-153 + IgG1-169 23isotype control 108

Example 23—Colocalization of HER2×HER2 Bispecific Antibodies withLysosomal Marker LAMP1 Analyzed by Confocal Microscopy

The HER2 downmodulation assay as described in Example 22 indicated thatHER2×HER2 bispecific antibodies were able to increase lysosomaldegradation of HER2. To confirm these findings, confocal microscopytechnology was applied. AU565 cells were grown on glass coverslips(thickness 1.5 micron, Thermo Fisher Scientific, Braunschweig, Germany)in standard tissue culture medium at 37° C. for 3 days. Cells werepre-incubated for 1 hour with 50 μg/mL leupeptin (Sigma) to blocklysosomal activity after which 10 μg/mL HER2 monospecific antibodies orHER2×HER2 bispecific antibodies were added. Also the combination of twomonospecific IgG1 antibodies (1:1) was tested at a final concentrationof 10 μg/mL. The cells were incubated for an additional 3 or 18 hours at37° C. Hereafter the cells were washed with PBS and incubated for 30min. at room temperature with 4% formaldehyde (Klinipath). Slides werewashed with blocking buffer (PBS supplemented with 0.1% saponin [Roche]and 2% BSA [Roche]) and incubated for 20 min with blocking buffercontaining 20 mM NH₄Cl to quench formaldehyde. Slides were washed againwith blocking buffer and incubated for 45 min at room temperature withmouse-anti-human CD107a (LAMP1) (BD Pharmingen) to stain/identifylysosomes. Following washing with blocking buffer, the slides wereincubated 30 min at room temperature with a cocktail of secondaryantibodies; goat-anti-mouse IgG-Cy5 (Jackson) and goat-anti-humanIgG-FITC (Jackson). Slides were washed again with blocking buffer andmounted overnight on microscope slides using 20 μL mounting medium (6gram Glycerol [Sigma] and 2.4 gram Mowiol 4-88 [Omnilabo] was dissolvedin 6 mL distilled water to which 12 mL 0.2M Tris [Sigma] pH8.5 was addedfollowed by incubation for 10 min at 50-60° C. Mounting medium wasaliquoted and stored at −20° C.). Slides were imaged with a Leica SPE-IIconfocal microscope (Leica Microsystems) equipped with a 63×1.32-0.6 oilimmersion objective lens and LAS-AF software. To allow forquantification of overlapping pixel intensities, saturation of pixelsshould be avoided. Therefore the FITC laser intensity was decreased to10%, smart gain was set at 830 V and smart offset was set at −9.48%. Byusing these settings, the bispecific antibodies were clearly visualizedwithout pixel saturation, but the monospecific antibodies were sometimesdifficult to detect. To compare lysosomal colocalization betweenmonospecific and bispecific antibodies, these settings were kept thesame for all analyzed confocal slides.

12-bit grayscale TIFF images were analyzed for colocalisation usingMetaMorph© software (version Meta Series 6.1, Molecular Devices Inc,Sunnyvale Calif., USA). FITC and Cy5 images were imported as stacks andbackground was subtracted. Identical thresholds settings were used(manually set) for all FITC images and all Cy5 images. Colocalisationwas depicted as the pixel intensity of FITC in the region of overlap(ROI), were the ROI is composed of all Cy5 positive regions. To comparedifferent slides stained with several HER2 antibodies, HER2×HER2bispecific antibodies or the combination of two different monospecificantibodies the images were normalized using the pixel intensity of Cy5.Goat-anti-mouse IgG-Cy5 was used to stain the lysosomal marker LAMP1(CD107a). The pixel intensity of LAMP1 should not differ between variousHER2 antibodies or the HER2×HER2 bispecific antibodies tested (one cellhad a pixel intensity of Cy5 of roughly 200.000).

Normalized values for colocalization of FITC andCy5=[(TPI-FITC×percentage FITC-Cy5colocalization)/100]×[200.000/TPI-Cy5]

In this formula, TPI stands for Total Pixel Intensity.

FIG. 11 and Table 11 present percentage of viable cells, as measured bythe FITC pixel intensity overlapping with Cy5 for various monospecificHER2 antibodies and HER2×HER2 bispecific antibodies. For each antibodyor bispecific molecule depicted, three different images were analyzedfrom one slide containing ˜1, 3 or >5 cells. Significant variation wasobserved between the different images within each slide. However, it wasevident that all HER2×HER2 bispecific antibodies demonstrate increasedcolocalisation with the lysosomal marker LAMP1, when compared with theirmonospecific counterparts. These results indicate that onceinternalized, HER2×HER2 bispecific antibodies are efficiently sortedtowards lysosomal compartments, making them suitable for a bispecificantibody drug conjugate approach.

TABLE 11 Mean FITC pixel intensities overlapping with Cy5 depicted asarbitrary units FITC pixel intensity in lysosomes antibody [arbitraryunits] Herceptin 0.218 IgG1-005-ITL 0.070 IgG1-025-ITL 0.268IgG1-153-ITL 0.102 IgG1-169-K409R 0.220 IgG1-005-ITL × IgG1-169-K409R0.531 IgG1-025-ITL × IgG1-005-K409R 0.347 IgG1-025-ITL × IgG1-153-K409R0.582 IgG1-025-ITL × IgG1-169-K409R 0.439 IgG1-153-ITL × IgG1-005-K409R0.494 IgG1-153-ITL × IgG1-169-K409R 0.604 IgG1-025 + IgG1-169 0.576IgG1-153 + IgG1-005 0.636 IgG1-153 + IgG1-169 0.626

Example 24—Inhibition of Proliferation of AU565 Cells Upon Incubationwith HER2 Monospecific or HER2×HER2 Bispecific Antibodies

The HER2×HER2 bispecific antibodies were tested for their ability toinhibit proliferation of AU565 cells in vitro. Due to the high HER2expression levels on AU565 cells (˜1,000,000 copies per cell asdetermined with Qifi-kit), HER2 is constitutively active in these cellsand thus not dependent on ligand-induced heterodimerization. In a96-wells tissue culture plate (Greiner bio-one, Frickenhausen, Germany),9.000 AU565 cells were seeded per well in the presence of 10 μg/mL HER2antibody or HER2×HER2 bispecific antibodies in serum-free cell culturemedium. As a control, cells were seeded in serum-free medium withoutantibody or bispecific antibodies. After three days, the amount ofviable cells was quantified with Alamarblue (BioSource International,San Francisco, US) according to the manufacturer's instructions.Fluorescence was monitored using the EnVision 2101 Multilabel reader(PerkinElmer, Turku, Finland) with standard Alamarblue settings. TheAlamarblue signal of antibody-treated cells was plotted as a percentagerelative to untreated cells.

FIG. 12 and table 12 depicts the fluorescent intensity of Alamarblue ofAU565 cells after incubation with HER2 antibodies and HER2×HER2bispecific antibodies. Herceptin® (trastuzumab) was included as positivecontrol and demonstrated inhibition of proliferation as described byJuntilla T T. et al., Cancer Cell 2009; 15: 429-440. All HER2×HER2bispecific antibodies were able to inhibit proliferation of AU565 cells.Bispecific antibodies: IgG1-005-ITL×IgG1-169-K409R andIgG1-025-ITL×IgG1-005-K409R were more effective compared to theirmonospecific antibody counterparts in this assay.

TABLE 12 Percentage viable AU565 cells after treatment with HER2 × HER2bispecific antibodies. percentage viable antibody cells Herceptin 62IgG1-005-ITL 91 IgG1-005-K409R 96 IgG1-025-ITL 79 IgG1-153-ITL 98IgG1-153-K409R 97 IgG1-169-K409R 63 IgG1-005-ITL × IgG1-169-K409R 49IgG1-025-ITL × IgG1-005-K409R 61 IgG1-025-ITL × IgG1-153-K409R 74IgG1-025-ITL × IgG1-169-K409R 76 IgG1-153-ITL × IgG1-005-K409R 71IgG1-153-ITL × IgG1-169-K409R 77 isotype control 95

Example 25—Her2×CD3 Bispecific Antibodies Tested in an In VitroCytotoxicity Assay

CD3 is a co-receptor in the T cell receptor complex expressed on matureT cells. Combination of a CD3 specific antibody Fab-arm with a tumorantigen specific antibody Fab-arm in a bispecific antibody would resultin the specific targeting of T cells to tumor cells, leading to T cellmediated tumor cell lysis. Likewise, CD3 positive T cells could betargeted to other derailed cells in the body, to infected cells ordirectly to pathogens.

HER2×CD3 bispecific antibodies were generated. Heavy and light chainvariable region sequences for the HER2 specific Fab-arm were asindicated for antibody 153 and 169 in Example 21. The following heavyand light chain variable region sequences for the CD3 specific Fab-armwere used:

YTH12.5 (Sequence as described by Routledge et al., Eur J Immunol. 1991, 21(11):2717-25.) SEQ VH EVQLLESGGGLVQPGGSL ID YTH12.5RLSCAASGFTFSSFPMAW NO: VRQAPGKGLEWVSTISTS 171 GGRTYYRDSVKGRFTISRDNSKNTLYLQMNSLRAED TAVYYCAKFRQYSGGFDY WGQGTLVTVSS SEQ VLDIQLTQPNSVSTSLGSTV ID YTH12.5 KLSCTLSSGNIENNYVHW NO: YQLYEGRSPTTMIYDDDK172 RPDGVPDRFSGSIDRSSN SAFLTIHNVAIEDEAIYF CHSYVSSFNVFGGGTKLT VL

huCLB-T3/4 (Sequence as described by Parrenet al., Res Immunol. 1991, 142(9):749-63.Minor amino acid substitutions wereintroduced to make the sequence resemble the closest human germline.)SEQ VH EVQLVESGGGLVKPGGSLRLSCA ID huCLB- ASGFTFSSYGMFWVRQAPGKGLE NO:T3/4 WVATISRYSRYIYYPDSVKGRFT 173 ISRDNAKNSLYLQMNSLRAEDTAVYYCARRPLYGSSPDYWGQGTLV TVSS SEQ VL EIVLTQSPATLSLSPGERATLSCS ID huCLB-ASSSVTYVHWYQQKPGQAPRLLIY NO: T3/4 DTSKLASGIPARFSGSGSGTDFTL 174TISSLEPEDFAVYYCFQGSGYPLT FGSGTKLEMR

All antibodies were expressed as IgG1,κ being modified in their Fcregions as follows: IgG1-HER2-153-K409R and IgG1-HER2-153-N297Q-K409R,IgG1-HER2-169-K409R, IgG1-hu-CLB-T3/4-F405L andIgG1-hu-CLB-T3/4-N297Q-F405L, IgG1-YTH12.5-F405L andIgG1-YTH12.5-N297Q-F405L.

Bispecific antibodies from these HER2 and CD3 specific antibodies weregenerated as described in Example 20 and tested in an in vitrocytotoxicity assay using AU565 cells. AU565 cells were cultured to nearconfluency. Cells were washed twice with PBS, and trypsinized for 5minutes at 37° C. 12 mL culture medium was added to inactivate trypsinand cells were spun down for 5 min, 800 rpm. Cells were resuspended in10 mL culture medium and a single cell suspension was made by passingthe cells through a cellstrainer. 100 μL of a 5×10⁵ cells/mL suspensionwas added to each well of a 96-well culture plate, and cells wereincubated at least 3 hrs at 37° C., 5% CO2 to allow adherence to theplate. Peripheral blood mononuclear cells (PBMC) were isolated fromblood from healthy volunteers using Leucosep 30 mL tubes, according tothe manufacturer's protocol (Greiner Bio-one). T cells were isolatedfrom PBMC preparations by negative selection using the Untouched HumanT-cells Dynabead kit (Dynal). Isolated cells were resuspended in culturemedium to a final concentration op 7×10⁶ cells/mL.

Culture medium was removed from the adhered AU565 cells, and replacedwith 50 μl/well 2× concentrated antibody-dilution and 50 μl/well 7×10⁶ Tcells/mL (ratio effector:target=7:1). Plates were incubated for 3 daysat 37° C., 5% CO₂. Supernatants were removed and plates were washedtwice with PBS. To each well 150 μL culture medium and 15 μL Alamar bluewas added. Plates were incubate for 4 hours at 37° C., 5% CO₂, andabsorbance was measured (Envision, Perkin Elmer).

FIG. 13 and table 13 shows that whereas control antibodies (Her2monospecific IgG1-Herceptin©, CD3 monospecific IgG1-YTH12.5 andmonospecific IgG1-huCLB-T3/4, irrelevant antigen monospecific IgG1-b12,and CD3×b12 bispecific antibodies) did not induce T cell mediatedcytotoxicity, bispecific (Duo) Her2×CD3 antibodies huCLB/Her2-153,huCLB/Her2-169, YTH12.5/Her2-153 and YTH12.5/Her2-169 induced dosedependent T cell mediated cytotoxicity of AU565 cells. Bispecificantibodies containing Her2-169 were more potent than those containingHer2-153.

Mutants of IgG1-hu-CLB-T3/4, IgG1-YTH12.5 and Her2-153 were madecontaining a N297Q mutation to remove a glycosylation site;glycosylation at this site is critical for IgG-Fcgamma receptorinteractions (Bolt S et al., Eur J Immunol 1993, 23:403-411). FIG. 13shows that N297Q mutation and therefore absence of Fc glycosylation ofHer2×CD3 bispecific antibodies YTH12.5/Her2-153 and huCLB/Her2-153 didnot impact the potential to induce dose dependent T cell mediatedcytotoxicity of AU565 cells.

TABLE 13 EC₅₀ values of cell kill induced by HER2 × CD3 bispecificantibodies. “Ndet” means not detected. EC50 antibody [ng/mL] HerceptinNdet Duo huCLB-Q/153-Q 10.55 Duo huCLB-Q/B12-Q Ndet huCLB-Q Ndet B12-QNdet Duo YTH12.5-Q/153-Q 10.73 Duo YTH12.5-Q/B12-Q Ndet YTH12.5-Q NdetB12-Q Ndet

Example 26—HER2 Downmodulation

To investigate if enhanced HER2 internalization induced by Group 3antibodies 098 and 153 also results in enhanced receptor downmodulation,AU565 cells were incubated with HER2 antibodies for 3 days, and analyzedfor presence of HER2. AU565 cells were seeded in a 24-wells tissueculture plate (100.000 cells/well) in normal cell culture medium andcultured for 3 days at 37° C. in the presence of 10 μg/mL HER2 antibody.After washing with PBS, cells were lysed by incubating 30 min at roomtemperature with 25 μL Surefire Lysis buffer (Perkin Elmer, Turku,Finland). Total protein levels were quantified using bicinchoninic acid(BCA) protein assay reagent (Pierce) according to the manufacturer'sprotocol. HER2 protein levels in the lysates were analyzed using aHER2-specific sandwich ELISA. Rabbit-anti-human HER2 intracellulardomain antibody (Cell Signaling) was used to capture HER2 andbiotinylated goat-anti-human HER2 polyclonal antibody (R&D), followed bystreptavidin-poly-HRP, were used to detect bound HER2. The reaction wasvisualized using 2,2′-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid(ABTS: dilute one ABTS tablet in 50 mL ABTS buffer [Roche Diagnostics,Almere, The Netherlands]) and stopped with oxalic acid (Sigma-Aldrich,Zwijndrecht, The Netherlands). Fluorescence at 405 nm was measured on amicrotiter plate reader (Biotek Instruments, Winooski, USA) and theamount of HER2 was expressed as a percentage relative to untreatedcells.

The results shown in FIG. 14 and Table 14 demonstrate that both Group 3antibodies (098 and 153) induced more than 50% HER2 downmodulation. Incontrast, antibodies 025, 169 and Herceptin barely induceddownmodulation (approximately 20% of untreated cells). This was in linewith enhanced internalization observed by antibodies 098 and 153.

TABLE 14 Antibody induced downmodulation of HER2 depicted as percentageHER2 compared to untreated cells % HER2 compared to antibody untreatedcells Herceptin 80 IgG1-1014-169 82 IgG1-1014-025 85 IgG1-1014-098 44IgG1-1014-153 50 isotype control 108

Example 27—Colocalization of HER2 Antibodies with Lysosomal Marker LAMP1Analyzed by Confocal Microscopy

The HER2 downmodulation assay as described in example 26 and theCypHer-5E based internalization assay as described in example 19indicated that HER2 antibodies from group 3 were more efficientlyinternalized and targeted towards lysosomes compared to antibodies fromGroups 1 and 2. However, in these experiments the confocal imaging wasdone with settings that allowed discriminating between monospecific andbispecific antibodies but not between different monospecific antibodies,in fact, with these settings monospecific antibodies could hardly bedetected. To be able to compare between the different monospecificantibodies, the confocal slides were measured again with increased gainsettings, to enhance fluorescence intensity. All other steps of theprocedure were the same as described in example 23.

The results are depicted in FIG. 15 and Table 15, and show that the FITCpixel intensity overlapping with Cy5 for various monospecific HER2antibodies. From each slide three different images were analyzedcontaining ˜1, 3 or >5 cells. Significant variation was observed betweenthe different images within each slide. Still, it was evident thatantibodies 098 and 153 were more efficiently targeted towards lysosomalcompartments, compared to 025, pertuzumab, 169 and Herceptin. Thiscorrelated well with the enhanced internalization and receptordegradation induced by these antibodies.

TABLE 15 Mean FITC pixel intensities overlapping with Cy5 depicted asarbitrary units FITC pixel intensity in lysosomes antibody [arbitraryunits] TH1014-098 0.522 TH1014-153 0.409 TH1014-025 0.248 TH1014-pert0.214 TH1014-169 0.255 Herceptin 0.236

Example 28—HER2 Extracellular Domain Shuffle Human-to-Chicken

To further define the HER2 binding regions recognized by antibodies fromthe four different cross-competition groups, a HER2 extracellular domainshuffle experiment was performed. To this end, a small gene-synthesislibrary with five constructs was generated, swapping the sequences ofdomain I, II, III or IV of the extracellular domain of human HER2 to thecorresponding sequence of chicken HER2 (Gallus Gallus isoform B NCBI:NP_001038126.1): 1) fully human HER2 (Uniprot P04626) hereafter namedhu-HER2, 2) hu-HER2 with chicken domain I (replacing amino acids (aa)1-203 of the human Her2 with the corresponding chicken Her2 region)hereafter named hu-HER2-ch(I), 3) hu-HER2 with chicken domain II(replacing amino acids (aa) 204-330 of the human Her2 with thecorresponding chicken Her2 region) hereafter named hu-HER2-ch(II), 4)hu-HER2 with chicken domain III (replacing aa 331-507 of the human Her2with the corresponding chicken Her2 region) hereafter namedhu-HER2-ch(III) and 5) hu-HER2 with chicken domain IV (replacing aa508-651 of the human Her2 with the corresponding chicken Her2 region)hereafter named hu-HER2-ch(IV). The human and chicken HER2 orthologsshow 67% homology in their extracellular domain with 62% homology indomain I, 72% homology in domain II, 63% homology in domain III and 68%homology in domain IV. The constructs were transiently transfected inthe Freestyle™ CHO—S(Invitrogen) cell line using Freestyle MAXtransfection reagent (Invitrogen) according to the instructions of themanufacturer, and transfected cells were cultured for 20 hours. HER2antibody binding to the transfected cells was analyzed by means of flowcytometry: The transfected CHO—S cells were harvested, washed with FACSbuffer and incubated with 10 μg/mL HER2 antibody (30 minutes on ice).Binding of HER2 antibodies was detected using a Phycoerythrin(PE)-conjugated goat-anti-human IgG antibody (Jackson). To check ifexpression between different batches was the same, cells were fixed andpermeabilized using Cytofix/Cytoperm solution (BD) accordingmanufacturer's instruction and stained with a rabbit-anti-humanintracellular HER2 antibody (DAKO) in combination with a secondaryPE-conjugated goat-anti-rabbit antibody (Jackson). An isotype controlantibody was used as negative control. Fluorescence was measured on aFACSCanto-II (BD) and binding curves were made by means of non-linearregression (sigmoidal dose-response with variable slope) using GraphPadPrism V4.03 software (GraphPad Software, San Diego, Calif., USA). Lossof binding was used as read out to identify which HER2 domains wererecognized by the different antibodies.

Exemplary binding curves for antibody 153 are shown in FIG. 16. Allbinding results are shown in Table 16. Group 1 HER2 antibodies 050, 084,169 and Herceptin showed loss of binding to Hu-HER2-ch(IV), but not tothe proteins with one of the remaining domains shuffled, demonstratingthat the epitopes of Group 1 mAbs reside in HER2 domain IV. Group 2antibodies 025, 091, 129 and pertuzumab showed only loss of binding toHu-HER2-ch(II), indicating that the epitope resides in HER2 domain II.Antibodies 098 and 153 were both defined to Group 3 in thecross-competition assay but showed some variation in the shuffleexperiment. Antibody 098 clearly showed loss of binding to Hu-HER2-ch(I)and a minor decrease in binding to Hu-HER2-ch(II), while 153 showed onlyloss of binding to Hu-HER2-ch(II). These data suggest that Group 3 mAbs098 and 153 can also bind, at least partially, to the HER2 domain II,with epitopes that possibly extend into HER2 domain I, as is the casefor 098.

TABLE 16 Summary of HER2 antibody binding to different HER2ECD receptorconstructs. HER2-domain shuffled Antibody Group FL I II III IV Herceptin1 +++ +++ +++ +++ − 050 1 +++ +++ +++ +++ − 084 1 +++ +++ +++ +++ − 1691 +++ +++ +++ +++ + Pertuzumab 2 +++ +++ + +++ +++ 025 2 +++ +++ − ++++++ 091 2 +++ +++ − +++ +++ 129 2 +++ +++ − +++ +++ 153 3 +++ +++ − ++++++ 098 3 +++ − ++ +++ +++ FL; hu-HER2, I; hu-HER2-ch(I), II;hu-HER2-ch(II), III; hu-HER2-ch(III), IV; hu-HER2-ch(IV). +++indicatesnormal binding, ++ indicates reduced EC₅₀ but the similar maximalbinding compared to binding observed to hu-HER2, +indicates reduced EC₅₀and reduced maximal binding detected compared to binding observed tohu-HER2, −indicates no binding.

Example 29—In Vivo Efficacy of HER2 HuMabs 091, 084 and 169 in NCI-N87Human Gastric Carcinoma Xenografts in SCID Mice

The in vivo effect of HER2-HuMabs 091 (cross-competition Group 2), 084and 169 (both cross-competition Group 1) on tumor growth and survival ina NCI-N87 human gastric carcinoma xenograft model in female CB.17 severecombined immunodeficiency (SCID) mice was determined. 10×10⁶ NCI-N87tumor cells in 50% matrigel were injected s.c. in female SCID mice, 10mice per group. Eight days after tumor inoculation, intravenoustreatment with HER2-HuMabs 091, 084, and 169 or control antibodyHuMab-HepC was started. In FIG. 17 (A) this is indicated as day 1, dayof treatment initiation. The first dose was at 40 mg/kg, followed by 10mg/kg on days 4, 8, 11, 15, 18, 22, and 25 after treatment initiation.

Tumor volume was determined at least 2 times per week. Volumes (mm³)were calculated from caliper (PLEXX) measurements as (width²×length)/2.

The results are depicted in FIGS. 17A and 17B which shows that the miceadministered with HuMab 084, 169 and 091 demonstrated slower tumorgrowth (A) and better survival (B) than the mice that received negativecontrol antibody HuMab-HepC. All treatments were well-tolerated.

Example 30—Therapeutic Treatment of BT-474 Breast Tumor Xenografts inBalb/C Nude Mice

The effect of therapeutic treatment of five different HER2 HuMabs onhuman subcutaneous BT-474 breast tumor xenografts in Balb/C nude micewas determined. BT-474 tumor cells were injected 24 to 72 hours after awhole body irradiation with a γ-source (1.8 Gy, Co60, BioMep, France).2×10⁷ BT-474 cells in 200 μl of RPMI 1640 containing matrigel (50:50,v:v; BD Biosciences) were injected subcutaneously into the right flankof female Balb/C nude mice. Body weight and tumor volume of the mice wasrecorded twice a week. Tumor volumes (mm³) were calculated from caliper(PLEXX) measurements as: (width²×length)/2.

Treatment with HER2 HuMabs was started when the tumors reached a meanvolume of 100-200 mm³. Tumor bearing mice were randomized into groups of8 mice. One group received twice weekly intravenous (i.v.) injections ofthe control mAb HuMab-HepC. Four other groups received twice weekly i.v.injections of HER2 HuMab 025, 129, 153 and 091, with a first dose of 20mg/kg and following 9 doses of 5 mg/kg.

The results are depicted in FIGS. 18A and 18B and show that BT-474 tumorgrowth was partially inhibited with HuMab 129 and HuMab 153 treatment(about 30 and 50% of inhibition compared to HuMab-HepC controltreatment). HuMab-025 and HuMab-091 strongly inhibited the BT-474 tumorgrowth and the time to reach a tumor volume of 800 mm³ was significantlydelayed by these antibodies. Survival was also improved in the HER2HuMAb receiving mice.

1. A monoclonal antibody which binds human epidermal growth factorreceptor 2 (HER2) and which comprises a VH region comprising a CDR3sequence selected from the group consisting of: a) SEQ ID NO:133, suchas the sequence of SEQ ID NO:4 (169); b) SEQ ID NO:11 (050, 049, 051,055); c) SEQ ID NO:130, such as the sequence of SEQ ID NO:18 (084); d)SEQ ID NO:136, such as the sequence of SEQ ID NO:25 (025); e) SEQ IDNO:139, such as the sequence of SEQ ID NO: 31 (091); f) SEQ ID NO:142,such as the sequence of SEQ ID NO:38 (129); g) SEQ ID NO:148, such asthe sequence of SEQ ID NO:48 (127); h) SEQ ID NO:52 (159); i) SEQ IDNO:145, such as the sequence of SEQ ID NO:59 (098); j) SEQ ID NO:154,such as the sequence of SEQ ID NO: 66 (153); and k) SEQ ID NO:151, suchas the sequence of SEQ ID NO: 73 (132). 2-3. (canceled)
 4. The antibodyof claim 1, comprising a VH region and a VL region selected from thegroups consisting of a) a VH region comprising the CDR1, CDR2 and CDR3sequences of SEQ ID NOs:2, 3 and 4, respectively; and a VL regioncomprising the CDR1, CDR2 and CDR3 sequences of SEQ ID NOs:6, DAS, andSEQ ID NO:7, respectively (169); b) a VH region comprising the CDR1,CDR2 and CDR3 sequences of SEQ ID NOs:9, 10 and 11, respectively; and aVL region comprising the CDR1, CDR2 and CDR3 sequences of SEQ ID NOs:13,AAS, and SEQ ID NO:14, respectively (050); c) a VH region comprising theCDR1, CDR2 and CDR3 sequences of SEQ ID NOs:16, 17 and 18, respectively;and a VL region comprising the CDR1, CDR2 and CDR3 sequences of SEQ IDNOs:20, VAS, and SEQ ID NO:21, respectively (084); d) a VH regioncomprising the CDR1, CDR2 and CDR3 sequences of SEQ ID NOs:23, 24 and25, respectively; and a VL region comprising the CDR1, CDR2 and CDR3sequences of SEQ ID NOs:27, AAS, and SEQ ID NO:28, respectively (025);e) a VH region comprising the CDR1, CDR2 and CDR3 sequences of SEQ IDNOs:30, 163 and 31, respectively; and a VL region comprising the CDR1,CDR2 and CDR3 sequences of SEQ ID NOs:33, AAS, and SEQ ID NO:34,respectively (091); f) a VH region comprising the CDR1, CDR2 and CDR3sequences of SEQ ID NOs:36, 37 and 38, respectively; and a VL regioncomprising the CDR1, CDR2 and CDR3 sequences of SEQ ID NOs:40, DAS, andSEQ ID NO:41, respectively (129); g) a VH region comprising the CDR1,CDR2 and CDR3 sequences of SEQ ID NOs:43, 44 and 45, respectively; and aVL region comprising the CDR1, CDR2 and CDR3 sequences of SEQ ID NOs:47,AAS, and SEQ ID NO:48, respectively (127); h) a VH region comprising theCDR1, CDR2 and CDR3 sequences of SEQ ID NOs:50, 51 and 52, respectively;and a VL region comprising the CDR1, CDR2 and CDR3 sequences of SEQ IDNOs:54, AAS, and SEQ ID NO:55, respectively (159); i) a VH regioncomprising the CDR1, CDR2 and CDR3 sequences of SEQ ID NOs:57, 58 and59, respectively; and a VL region comprising the CDR1, CDR2 and CDR3sequences of SEQ ID NOs:60, AAS, and SEQ ID NO:61, respectively (098);j) a VH region comprising the CDR1, CDR2 and CDR3 sequences of SEQ IDNOs:64, 65 and 66, respectively; and a VL region comprising the CDR1,CDR2 and CDR3 sequences of SEQ ID NOs:68, DAS, and SEQ ID NO:69,respectively (153); and k) a VH region comprising the CDR1, CDR2 andCDR3 sequences of SEQ ID NOs:71, 72 and 73, respectively; and a VLregion comprising the CDR1, CDR2 and CDR3 sequences of SEQ ID NOs:75,DAS, and SEQ ID NO:76, respectively (132). 5-8. (canceled)
 9. Amonoclonal antibody comprising a VH region and a VL region selected fromthe group consisting of: a) a VH region comprising the sequence of SEQID NO:1 and, preferably, a VL region comprising the sequence of SEQ IDNO:5 (169); b) a VH region comprising the sequence of SEQ ID NO:8 and,preferably, a VL region comprising the sequence of SEQ ID NO:12 (050);c) a VH region comprising the sequence of SEQ ID NO:15 and, preferably,a VL region comprising the sequence of SEQ ID NO:19 (084); d) a VHregion comprising the sequence of SEQ ID NO:77 and, preferably, a VLregion comprising the sequence of SEQ ID NO:78 (049); e) a VH regioncomprising the sequence of SEQ ID NO:79 and, preferably, a VL regioncomprising the sequence of SEQ ID NO:80 (051); f) a VH region comprisingthe sequence of SEQ ID NO:81 and, preferably, a VL region comprising thesequence of SEQ ID NO:82 (055); g) a VH region comprising the sequenceof SEQ ID NO:83 and, preferably, a VL region comprising the sequence ofSEQ ID NO:84 (123); h) a VH region comprising the sequence of SEQ IDNO:85 and, preferably, a VL region comprising the sequence of SEQ IDNO:86 (161); i) a VH region comprising the sequence of SEQ ID NO:87 and,preferably, a VL region comprising the sequence of SEQ ID NO:88 (124);j) a VH region comprising the sequence of SEQ ID NO:22 and, preferably,a VL region comprising the sequence of SEQ ID NO:26 (025); k) a VHregion comprising the sequence of SEQ ID NO:29 and, preferably, a VLregion comprising the sequence of SEQ ID NO:32 (091); l) a VH regioncomprising the sequence of SEQ ID NO:35 and, preferably, a VL regioncomprising the sequence of SEQ ID NO:39 (129); m) a VH region comprisingthe sequence of SEQ ID NO:89 and, preferably, a VL region comprising thesequence of SEQ ID NO:90 (001); n) a VH region comprising the sequenceof SEQ ID NO:91 and, preferably, a VL region comprising the sequence ofSEQ ID NO:92 (143); o) a VH region comprising the sequence of SEQ IDNO:93 and, preferably, a VL region comprising the sequence of SEQ IDNO:94 (019); p) a VH region comprising the sequence of SEQ ID NO:95 and,preferably, a VL region comprising the sequence of SEQ ID NO:96 (021);q) a VH region comprising the sequence of SEQ ID NO:97 and, preferably,a VL region comprising the sequence of SEQ ID NO:98 (027); r) a VHregion comprising the sequence of SEQ ID NO:99 and, preferably, a VLregion comprising the sequence of SEQ ID NO:100 (032); s) a VH regioncomprising the sequence of SEQ ID NO:101 and, preferably, a VL regioncomprising the sequence of SEQ ID NO:102 (035); t) a VH regioncomprising the sequence of SEQ ID NO:103 and, preferably, a VL regioncomprising the sequence of SEQ ID NO:104 (036); u) a VH regioncomprising the sequence of SEQ ID NO:105 and, preferably, a VL regioncomprising the sequence of SEQ ID NO:106 (054); v) a VH regioncomprising the sequence of SEQ ID NO:106 and, preferably, a VL regioncomprising the sequence of SEQ ID NO:108 (094); w) a VH regioncomprising the sequence of SEQ ID NO:46 and, preferably, a VL regioncomprising the sequence of SEQ ID NO:49 (127); x) a VH region comprisingthe sequence of SEQ ID NO:49 and, preferably, a VL region comprising thesequence of SEQ ID NO:53 (159); y) a VH region comprising the sequenceof SEQ ID NO:56 and, preferably, a VL region comprising the sequence ofSEQ ID NO:60 (098); z) a VH region comprising the sequence of SEQ IDNO:63 an, preferably, a VL region comprising the sequence of SEQ IDNO:67 (153); aa) a VH region comprising the sequence of SEQ ID NO:70and, preferably, a VL region comprising the sequence of SEQ ID NO:74(132); bb) a VH region comprising the sequence of SEQ ID NO:109 and,preferably, a VL region comprising the sequence of SEQ ID NO:110 (105);cc) a VH region comprising the sequence of SEQ ID NO:111 and,preferably, a VL region comprising the sequence of SEQ ID NO:112 (100);dd) a VH region comprising the sequence of SEQ ID NO:113 and,preferably, a VL region comprising the sequence of SEQ ID NO:114 (125);ee) a VH region comprising the sequence of SEQ ID NO:115 and,preferably, a VL region comprising the sequence of SEQ ID NO:116 (162);ff) a VH region comprising the sequence of SEQ ID NO:117 and,preferably, a VL region comprising the sequence of SEQ ID NO:118 (033);gg) a VH region comprising the sequence of SEQ ID NO:119 and,preferably, a VL region comprising the sequence of SEQ ID NO:120 (160)hh) a VH region comprising the sequence of SEQ ID NO:121 and,preferably, a VL region comprising the sequence of SEQ ID NO:122 (166);ii) a VH region comprising the sequence of SEQ ID NO:123 and,preferably, a VL region comprising the sequence of SEQ ID NO:124 (152);jj) a VH region comprising the sequence of SEQ ID NO:125 and,preferably, a VL region comprising the sequence of SEQ ID NO:126 (167);and kk) a variant of any of said antibodies, wherein said variantpreferably has at most 1, 2 or 3 amino-acid modifications, morepreferably amino-acid substitutions, such as conservative amino acidsubstitutions and substitutions where the new amino acid is one at thesame position in an aligned sequence in FIG. 1 or 2, particularly atpositions indicated by “X” in the corresponding consensus sequence.10-20. (canceled)
 21. A bispecific antibody comprising theantigen-binding region of an antibody as defined in claim 1, and asecond antigen-binding site having a different binding specificity, suchas a binding specificity for a human effector cell, a human Fc receptor,a T cell receptor or a non-blocking epitope of HER2. 22-27. (canceled)28. The antibody of claim 1, wherein the antibody is a full-lengthantibody, preferably an IgG1 antibody, in particular an IgG1,κ antibody.29. The antibody of claim 1, wherein the antibody is conjugated toanother moiety, such as a cytotoxic moiety, a radioisotope, a drug, or acytokine.
 30. The antibody of claim 29, wherein the cytotoxic moiety isselected from the group consisting of taxol; cytochalasin B; gramicidinD; ethidium bromide; emetine; mitomycin; etoposide; tenoposide;vincristine; vinblastine; colchicin; doxorubicin; daunorubicin;dihydroxy anthracin dione; a tubulin-inhibitor such as maytansine or ananalog or derivative thereof; mitoxantrone; mithramycin; actinomycin D;1-dehydrotestosterone; a glucocorticoid; procaine; tetracaine;lidocaine; propranolol; puromycin; calicheamicin or an analog orderivative thereof an antimetabolite such as methotrexate, 6mercaptopurine, 6 thioguanine, cytarabine, fludarabin, 5 fluorouracil,decarbazine, hydroxyurea, asparaginase, gemcitabine, or cladribine; analkylating agent such as mechlorethamine, thioepa, chlorambucil,melphalan, carmustine (BSNU), lomustine (CCNU), cyclophosphamide,busulfan, dibromomannitol, streptozotocin, dacarbazine (DTIC),procarbazine, mitomycin C, cisplatin, carboplatin, duocarmycin A,duocarmycin SA, rachelmycin (CC-1065), or an analog or derivativethereof; an antibiotic such as dactinomycin, bleomycin, daunorubicin,doxorubicin, idarubicin, mithramycin, mitomycin, mitoxantrone,plicamycin, anthramycin (AMC)); an antimitotic agent such as monomethylauristatin E or F or an analog or derivative thereof; diphtheria toxinand related molecules such as diphtheria A chain and active fragmentsthereof and hybrid molecules, ricin toxin such as ricin A or adeglycosylated ricin A chain toxin, cholera toxin, a Shiga-like toxinsuch as SLT I, SLT II, SLT IIV, LT toxin, C3 toxin, Shiga toxin,pertussis toxin, tetanus toxin, soybean Bowman-Birk protease inhibitor,Pseudomonas exotoxin, alorin, saporin, modeccin, gelanin, abrin A chain,modeccin A chain, alpha-sarcin, Aleurites fordii proteins, dianthinproteins, Phytolacca americana proteins such as PAPI, PAPII, and PAP S,Momordica charantia inhibitor, curcin, crotin, Sapaonaria officinalisinhibitor, gelonin, mitogellin, restrictocin, phenomycin, and enomycintoxins; ribonuclease (RNase); DNase I, Staphylococcal enterotoxin A;pokeweed antiviral protein; diphtherin toxin; and Pseudomonas endotoxin.31. The antibody of claim 29, which is conjugated to a cytotoxic moietyselected from the group consisting of maytansine, calicheamicin,duocarmycin, rachelmycin (CC-1065), monomethyl auristatin E, monomethylauristatin F or an analog, derivative, or prodrug of any thereof. 32.The antibody of claim 29, which is conjugated to a cytokine selectedfrom the group consisting of IL-2, IL-4, IL-6, IL-7, IL-10, IL-12,IL-13, IL-15, IL-18, IL-23, IL-24, IL-27, IL-28a, IL-28b, IL-29, KGF,IFNα, IFNβ, IFNγ, GM-CSF, CD40L, Flt3 ligand, stem cell factor,ancestim, and TNFα.
 33. (canceled)
 34. A nucleotide sequence encodingone or more of the amino acid sequences selected from the groupconsisting of SEQ ID NO: 1, 5, 8, 12, 15, 19, 22, 26, 29, 32, 35, 39,42, 46, 49, 53, 56, 60, 63, 67, 70, 74, 77, 78, 79, 80, 81, 82, 83, 84,85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101,102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115,116, 117, 118, 119, 120, 121, 122, 123, 124, 125 and
 126. 35. Anexpression vector comprising a nucleotide sequence according to claim34, wherein the vector further encodes an operatively-linked constantregion of a light chain, constant region of a heavy chain or both lightand heavy chains of an antibody.
 36. A recombinant eukaryotic orprokaryotic host cell which produces an antibody as defined in claim 1.37. A pharmaceutical composition comprising the antibody of claim 1 anda pharmaceutically acceptable carrier. 38-45. (canceled)
 46. A methodfor inhibiting growth and/or proliferation of one or more tumor cellsexpressing HER2, comprising administration, to an individual in needthereof, of an antibody according to claim
 1. 47. The method of claim46, wherein the one or more tumor cells coexpress HER2 and EGFR and/orHER3.
 48. A method for treating cancer, comprising a) selecting asubject suffering from a cancer comprising tumor cells co-expressingHER2 and EGFR and/or HER3, and b) administering to the subject theantibody according to claim
 1. 49. The method of claim 48, wherein thecancer is selected from the group consisting of breast cancer,colorectal cancer, endometrial/cervical cancer, lung cancer, malignantmelanoma, ovarian cancer, pancreatic cancer, prostate cancer, testiscancer, a soft-tissue tumor such as synovial sarcoma, and bladdercancer.
 50. A method for producing an antibody, said method comprisingthe steps of a) culturing a host cell of claim 36, and b) purifying theantibody from the culture media.
 51. A method for detecting the presenceof HER2 in a sample, comprising: contacting the sample with an antibodyof claim 1 under conditions that allow for formation of a complexbetween the antibody and HER2; and analyzing whether a complex has beenformed.
 52. A kit for detecting the presence of HER2 in a samplecomprising the antibody of claim 1; and instructions for use of the kit.